334 code. Please help
- Thread starter 94stroked331
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The new codes make sense.
You definitely want to figure out the vac leak situation. This can cause the hanging between shifts, and could be throwing off your long-term trim enough to cause other issues (let alone not actuating the EGR valve properly, when applicable).
Does the vac reading actually oscillate quickly, or where you giving a range of values seen while at light to moderate cruise?
You definitely want to figure out the vac leak situation. This can cause the hanging between shifts, and could be throwing off your long-term trim enough to cause other issues (let alone not actuating the EGR valve properly, when applicable).
Does the vac reading actually oscillate quickly, or where you giving a range of values seen while at light to moderate cruise?
That was at idle, and it stays at about 10 for maybe 2-4 seconds and then goes to 14 for maybe 1 sec and then drops to 8 for maybe 1 sec then back to 10. The book says it should be between 17 and 22.
As far as vacuum leak I can't seem to find one. I have sprayed starting fluid spairingly on every vacuum lin and connection. I have also been listening. I guess my next step will be to start pulling lines off and to see which ones do not make a difference. Maybe I routed the lines wrong when i reinstalled the engine. I think they are correct but the Holley systemax was much dofferent than the OE intake.
As far as vacuum leak I can't seem to find one. I have sprayed starting fluid spairingly on every vacuum lin and connection. I have also been listening. I guess my next step will be to start pulling lines off and to see which ones do not make a difference. Maybe I routed the lines wrong when i reinstalled the engine. I think they are correct but the Holley systemax was much dofferent than the OE intake.
Vac schematic
The fluctuation makes me wonder if you have a valve train issue. Check out the following link and see which (if any) best fits:
How to Use and Interpret a Vacuum Gauge
The fluctuation makes me wonder if you have a valve train issue. Check out the following link and see which (if any) best fits:
How to Use and Interpret a Vacuum Gauge
hotcobra03
Active Member
cam?
im not an engine guy,but thier has to be a reason for the cats to turn red?are you sure the cam was right for the firing order? low vacuum is a sign of low timing also?in that link below 15 was retarted timing...Are you the one who installed the engine?Something doesnt sound right...what about fuel pressure and injector size?
im not an engine guy,but thier has to be a reason for the cats to turn red?are you sure the cam was right for the firing order? low vacuum is a sign of low timing also?in that link below 15 was retarted timing...Are you the one who installed the engine?Something doesnt sound right...what about fuel pressure and injector size?
Okay, I hooked the vacuum gauge to the line going into the pcv. It seems to hold steady at 8 with light flickering most like scenerio 3 except at 8 instead of 15. however upon acceleration the gauge drops to zero and then back up. If i hold it at about 25 rpm it stays steady at 15 or so. As far as a valvetrain problem I guess anything is possible although I have new AFR heads complete with valvetrain and 1.6 roller rockers. There is nothing (engine wise) that is not new. I have only put 250 miles on since rebuild... Definately pulling my hair out!
Oh as far as fuel pressure it is set at 40. I can't remember what size the injectors are. It seems like they are 32lbs. I will have to find my paper work, I think it is in a file at work. Whatever they are I got the MAF to match. Timing is set to 13. Yes I installed the engine as well as built it. As far as power, it has tons of power. I just can't get these little bugs worked out. And the cam. Yes I have the cam card in front of me now.
Okay, again I sprayed enough starting fluid around the intake and all vacuum hoses to ignite a small cambodian village with NO change. I also changed the timing between like 5 and 20 with no change either. Set it back to 13. Maybe we are back to the EVR? As far as a vacuum leak I am stumped. Maybe Autozone or one of those places will "loan" a vacuum pump. I hate to spend $60 on one and then have to turn around and spend another $60 on an EVR.
hotcobra03
Active Member
vacuum
dude everything you just said was my next thought,,,frpp has a free download that has some good footnotes in it as to injectors+maf/high exhaust temps,,but i just did the heads on my 03 cobra and found 3 mini hoses bad..i found them by removing the complete vacuum harness and i blew and sucked each hose...i was shocked to find 3 bad lines on a new car...yours is wat 10yrs older...a clogged or restricted line is easy to find when its removed
dude everything you just said was my next thought,,,frpp has a free download that has some good footnotes in it as to injectors+maf/high exhaust temps,,but i just did the heads on my 03 cobra and found 3 mini hoses bad..i found them by removing the complete vacuum harness and i blew and sucked each hose...i was shocked to find 3 bad lines on a new car...yours is wat 10yrs older...a clogged or restricted line is easy to find when its removed
Alright I am chipping away at it. I cleaned the IAC and checked the TPS. The TPS was off a little. I have an adjustable housing for the TPS. I adjusted it to .6 at idle. It was 1.5 before. At full throtttle it is about 4.7. It idles MUCH better. I have it idleing at about 1000 RPMs(this may be too high???). It still surges at cruise speed and when slowing down and it still doesn't decrease RPM when I press the clutch while shifting. Taking the oil filler cap off there is no suction. (I don't know if this matters, but I heard it was a sign of an internal intake leak if there was vacuum at oil filler???) I will look forward to your advice tomorrow.
I guess my nest step is to take ALL of the vacuum lines off and test individually or maybe I will just get a new EVR first. I guess $60 won't break me. No more working on the car tonight, just more research. I will be back on it sometime this week, but I promise I will update when I find the problem. And yes it is 15 years old.
Oh and by the way, no more RPM flucuations at idle.
I guess my nest step is to take ALL of the vacuum lines off and test individually or maybe I will just get a new EVR first. I guess $60 won't break me. No more working on the car tonight, just more research. I will be back on it sometime this week, but I promise I will update when I find the problem. And yes it is 15 years old.
Oh and by the way, no more RPM flucuations at idle.
hotcobra03
Active Member
research
just a thought as you search...i have been learning for hission50,joel5.0,and jrichker...they all give great advise,,,but remember when you ask about a problem,i answer to the question,,(i assume you have done the basic`s already)just one exsample..another person did an engine swap and just put back intake and up back on without re-adjusting to different engine..his issuses were close to yours as to driveability,,,7 months later and many ,many replys,,it was base timing/idle not set right,,yours sounds like a timing/fuel problem...im stuck on why did cats get red? yes you passed emissions,but with 200 miles on it maybe you got lucky thier..now with cats gutted,if you stand behind car does it smell like its running rich?do your eyes warter? With my 03 i had valve issuses and very strong odor of gas ,,,i dont have cats and can stand behind car while its idling?
just a thought as you search...i have been learning for hission50,joel5.0,and jrichker...they all give great advise,,,but remember when you ask about a problem,i answer to the question,,(i assume you have done the basic`s already)just one exsample..another person did an engine swap and just put back intake and up back on without re-adjusting to different engine..his issuses were close to yours as to driveability,,,7 months later and many ,many replys,,it was base timing/idle not set right,,yours sounds like a timing/fuel problem...im stuck on why did cats get red? yes you passed emissions,but with 200 miles on it maybe you got lucky thier..now with cats gutted,if you stand behind car does it smell like its running rich?do your eyes warter? With my 03 i had valve issuses and very strong odor of gas ,,,i dont have cats and can stand behind car while its idling?
There is a gas smell but it's not too strong. It smelled the same way before I gutted the cats. Everything that I read pointed towards stopped up converters(as far as them glowing, it was the pre cats glowing not the big ones). They do have 230K miles on them...
Another thing I have noticed is that there is a little bit of oil in the throttle body when I take the air inlet off coming from the MAF. I guess it is sucking it in from the hose connected to the oil filler? Is this bad? Does it mean I have a lower intake leak? If so would this cause my low vacuum when I hook the gauge up to the hose going to the PCV?
Can you say frustrating?
As far as the intake goes I put a new Holly Systemax on there. I didn't use the stock one. What adjusting should I have done?
Another thing I have noticed is that there is a little bit of oil in the throttle body when I take the air inlet off coming from the MAF. I guess it is sucking it in from the hose connected to the oil filler? Is this bad? Does it mean I have a lower intake leak? If so would this cause my low vacuum when I hook the gauge up to the hose going to the PCV?
Can you say frustrating?
As far as the intake goes I put a new Holly Systemax on there. I didn't use the stock one. What adjusting should I have done?
You can often 'loan out' a vac pump from the parts stores. Otherwise, they're about 40 bucks at parts stores (or like 20 on sale at Harbor Freight). They're really helpful for doing brake fluid flushes or if you overfill an Auto trans, so it's a great tool to have (this won't be a one-time tool if you do buy one).
Oil in the inlet is generally a lack of ring seal (low tension rings). But your PCV isnt as active as it could be with the lower vacuum, and the engine is still close to being in a break-in, depending upon how it was run already. You can add a separator later on if you want.
I still think the vac issue is the place to look. It's a real PITA to find those leaks, like hotcobra03 noted. Your cannister purge line is probably rotted too (the fuel rots the line). Check that as a source of leakage. Otherwise, I remove one line at a time, cap it's port, and watch my gauge to see if the reading increased. Otherwise, checking pushrod adjustment is another place to go.
Oil in the inlet is generally a lack of ring seal (low tension rings). But your PCV isnt as active as it could be with the lower vacuum, and the engine is still close to being in a break-in, depending upon how it was run already. You can add a separator later on if you want.
I still think the vac issue is the place to look. It's a real PITA to find those leaks, like hotcobra03 noted. Your cannister purge line is probably rotted too (the fuel rots the line). Check that as a source of leakage. Otherwise, I remove one line at a time, cap it's port, and watch my gauge to see if the reading increased. Otherwise, checking pushrod adjustment is another place to go.
hotcobra03
Active Member
some vacuum tests
use what you can?you still have mufflers on the car?2003 PCED OBD SECTION 5: Pinpoint Tests
Procedure revision date: 06/11/2003
--------------------------------------------------------------------------------
HF: Catalyst Efficiency Monitor and Exhaust Systems HF: Introduction
--------------------------------------------------------------------------------
HF1 DTCs P0420 OR P0430: CHECK FOR MISFIRE DETECTION MONITOR DTCS
NOTE 1: Be sure customer has not:
Refueled vehicle with leaded gasoline.
Noticed high vehicle oil consumption. (Engines that consume oil at a high rate will deposit high levels of phosphorus on the catalyst and reduce the catalyst efficiency)
NOTE 2: If entering this Pinpoint Test for symptoms only, immediately GO to HF5 .
NOTE 3: Internal deterioration of a catalytic converter is usually caused by abnormal engine operation upstream of the catalyst. Events that can produce higher than normal temperatures in the catalyst are particularly suspect. For example, misfiring can cause higher than normal catalyst operating temperatures.
Retrieve and record all Continuous Memory DTCs (MIL and non-MIL).
Were any of the following Misfire Detection Monitor DTCs recorded: P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309, P0310, P0315, P0316 and P1309?
Yes No
GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the Misfire Detection Monitor DTCs. GO to HF2 .
HF2 CHECK FOR HO2S DTCS
NOTE: Incorrect HO2S signal input (such as rich/lean input signal when the engine is operating under lean/rich conditions) can cause an abnormal temperature increase in the catalyst. Refer to Section 1 , Heated Oxygen Sensor (HO2S) Monitor for possible HO2S DTCs.
Were there any HO2S DTCs (not including the initial P0420 or P0430 DTCs)?
Yes No
GO to, Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the HO2S DTCs. GO to HF3 .
HF3 CHECK FOR ECT OR CHT SENSOR DTCS
NOTE: ECT or CHT sensor DTCs can indicate that the thermostat is not operating correctly or that the engine coolant level is not filled to specification, producing above normal operating temperatures.
Were any of the following ECT or CHT sensor DTCs recorded in HF1: P0117, P0118, P0125, P0128, P1117, P1285, P1288, P1289, P1290 and P1299?
Yes No
GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the ECT or CHT sensor DTCs. GO to HF4 .
HF4 CHECK FOR ANY OTHER DTCS
Were any other DTCs recorded in HF1 (not including the initial P0420 or P0430 DTCs)?
Yes No
GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the DTCs. GO to HF5 .
HF5 CHECK REAR HO2S WIRING AND PCM CONNECTIONS
NOTE: If the electrical connections of the rear HO2S are interchanged/crossed, the Catalyst Efficiency Monitor Test will fail.
Inspect the wiring of each rear HO2S for proper routing and connection.
Disconnect the PCM, inspect for damaged or pushed out pins, corrosion and loose wires.
Are there any concerns with the HO2S wiring or the PCM connection?
Yes No
REPAIR any wiring or connection concerns. For PCM pin concerns, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). No Electronic EC root causes related to the DTCs or symptoms. GO to HF6 .
HF6 CHECK FUEL PRESSURE
WARNING: THE FUEL SYSTEM WILL REMAIN PRESSURIZED WHEN THE ENGINE IS NOT RUNNING. TO PREVENT INJURY OR FIRE, USE CAUTION WHEN WORKING ON THE FUEL SYSTEM.
NOTE: Fuel pressures above specification can produce an abnormally rich air/fuel mixture. The rich air/fuel mixture can cause higher than normal catalyst operating temperatures.
RETURN FUEL SYSTEM
Inspect the vacuum hose going to the fuel pressure regulator for proper installation and cracks. Repair as necessary.
Verify vacuum source to fuel pressure regulator.
MECHANICAL RETURNLESS FUEL SYSTEM
If applicable, inspect the vacuum hose going to the fuel rail pulse damper for proper installation and cracks. Repair as necessary.
Install fuel pressure gauge. NOTE: On Electronic Returnless Fuel System, the fuel pressure can be monitored by scan tool using the Fuel Rail Pressure (FRP) sensor PID.
Start and run the engine at idle. Record the fuel pressure.
Increase engine speed to 2500 rpm and maintain for one minute. Record the fuel pressure. GO to Pinpoint Test HC and compare fuel pressure to the Fuel Pressure Specification Chart at the beginning of the pinpoint.
Key off.
Was the fuel pressure within specifications?
Yes No
Fuel pressure is OK. If applicable, REMOVE the fuel pressure gauge. GO to HF7 . Fuel pressure is out of specification.
GO to HC4 , Fuel Delivery Systems in Section 5 for diagnosis.
HF7 CHECK FOR OBVIOUS LEAK SOURCES IN THE EXHAUST SYSTEM
NOTE: If a catalyst is in series with a leaking exhaust system, it can fail the Catalyst Efficiency Monitor test.
Inspect the following for leaks, cracks, loose connections or punctures:
Exhaust manifold.
Front exhaust pipe.
Rear exhaust pipe.
Muffler/tailpipe assembly.
Are the above components free of cracks and punctures, etc.?
Yes No
GO to HF8 . REPAIR the leak source(s). COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
HF8 CHECK FOR OBVIOUS RESTRICTIONS IN THE EXHAUST SYSTEM
A slight pressure in the exhaust system is normal, but excessive exhaust back pressure seriously affects engine operation. Causes of high exhaust back pressure are dents or obstructions in the exhaust pipe, a plugged catalytic converter or muffler.
Inspect the following for dents, areas of collapsed material and unusual bending:
Front and rear exhaust pipes.
Catalytic converter.
Muffler/tailpipe assembly.
Are the components free of dents and areas of collapsed or unusual bending or damaged?
Yes No
GO to HF9 . REPAIR the restricted component(s) as necessary. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
HF9 CHECK FOR EXCESSIVE EXHAUST BACK PRESSURE
If available install a exhaust back pressure tester and follow tool manufacturer installation and testing instructions.
NOTE: If no tester is available. GO to HF10 .
Typical exhaust back pressure (when measured near the exhaust manifold and at normal engine operating temperature) should not exceed 20.7 kPa (3 PSI) at idle and 55.2 kPa (8 PSI) at WOT under load.
Did exhaust back pressure test indicate a restriction?
Yes No
REPAIR the restricted component(s) as necessary. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3 , Symptom Charts No indications of restrictions or leaks have been detected in the exhaust system. If here because of DTCs P0420 or P0430, the catalytic converter is chemically inactive. REPLACE the catalyst that is located between the monitored H02S Sensors, only for the bank referenced, (P0420 Bank 1), (P0430 Bank 2). Do not replace any unmonitored catalyst unless it is serviced as an assembly. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3 , Symptom Charts.
HF10 CHECK MANIFOLD VACUUM FOR INDICATION OF EXCESSIVE EXHAUST SYSTEM RESTRICTION
Attach a vacuum gauge to the intake manifold vacuum source.
Monitor RPM with scan tool or tachometer.
Observe the vacuum gauge needle while completing the following:
NOTE: The vacuum gauge reading may be normal when the engine is first started and idling. However, excessive restriction in the exhaust system will cause intake manifold vacuum to decrease with the engine at a steady/constant idle speed.
Start the engine and gradually increase the engine speed to 2000 rpm with the transmission in NEUTRAL.
Decrease engine speed to base idle rpm.
Key off.
Did manifold vacuum rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes No
GO to HF11 . Manifold vacuum did not reach an acceptable level. GO to HF12 to check for excessive restriction in the exhaust system.
HF11 CHECK MANIFOLD VACUUM FOR INDICATION OF MODERATE EXHAUST SYSTEM RESTRICTION
Key on, engine idling.
Increase the engine speed gradually from base idle rpm to 2000 rpm with the transmission in NEUTRAL.
Observe the speed the vacuum gauge needle rises, while maintaining the increased engine rpm.
NOTE 1: On a non-restricted exhaust system, the vacuum gauge needle will rise quickly to the normal range as the increased rpm is maintained.
NOTE 2: On a restricted exhaust system, the vacuum gauge needle will rise slowly to the normal range as the increased rpm is maintained.
NOTE 3: The rate of speed the vacuum gauge needle rises to the normal range is slower on a restricted system than on a non-restricted system as the increased rpm is maintained.
Decrease engine speed to base idle rpm.
Key off.
Is the rate of speed that the vacuum gauge needle rises back to the normal range (above 54 kPa (16 inches-Hg)) much slower than that of a non-restricted system?
Yes No
A moderate restriction may be present. GO to HF12 . No indications of restrictions or leaks have been detected in the exhaust system. If here because of DTCs P0420 or P0430, the catalytic converter is chemically inactive. REPLACE the catalyst that is located between the monitored H02S Sensors, only for the bank referenced, (P0420 Bank 1), (P0430 Bank 2). Do not replace any unmonitored catalyst unless it is serviced as an assembly. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3 , Symptom Charts.
HF12 CHECK MANIFOLD VACUUM WITH EXHAUST MANIFOLD DISCONNECTED FOR INDICATION OF A RESTRICTION
NOTE: An intake manifold gasket leak can also cause the vacuum gauge needle to remain well below the normal range.
Disconnect exhaust system immediately after the exhaust manifold.
GO to HF10 and repeat the vacuum measurement.
Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes No
The exhaust system restriction is downstream of the exhaust manifold. RECONNECT exhaust system at exhaust manifold. GO to HF13 . A restriction is present in the exhaust manifold. INSPECT each exhaust port for casting flash/restrictions by dropping a length of chain into it (NOTE: Do not use a wire or lamp to check the ports. The restriction can be small enough for both to pass through, but large enough to cause excessive back-pressure at high engine rpm.) REPLACE the exhaust manifold if unable to remove the casting flash/restriction. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
HF13 CHECK MANIFOLD VACUUM WITH MUFFLER/TAILPIPE ASSEMBLY DISCONNECTED FOR INDICATION OF A RESTRICTION
Disconnect muffler/tailpipe assembly from the catalytic converter.
GO to HF10 to repeat the vacuum measurement.
Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes No
There is a restriction in the muffler/tailpipe assembly. REPLACE the muffler/tailpipe assembly. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). There is a restriction in the catalytic converter. REPLACE the catalytic converter. NOTE: On vehicle applications where their is more than one catalyst, REPLACE only the damaged catalyst assembly. INSPECT the muffler to be certain converter debris has not entered. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
--------------------------------------------------------------------------------
use what you can?you still have mufflers on the car?2003 PCED OBD SECTION 5: Pinpoint Tests
Procedure revision date: 06/11/2003
--------------------------------------------------------------------------------
HF: Catalyst Efficiency Monitor and Exhaust Systems HF: Introduction
--------------------------------------------------------------------------------
HF1 DTCs P0420 OR P0430: CHECK FOR MISFIRE DETECTION MONITOR DTCS
NOTE 1: Be sure customer has not:
Refueled vehicle with leaded gasoline.
Noticed high vehicle oil consumption. (Engines that consume oil at a high rate will deposit high levels of phosphorus on the catalyst and reduce the catalyst efficiency)
NOTE 2: If entering this Pinpoint Test for symptoms only, immediately GO to HF5 .
NOTE 3: Internal deterioration of a catalytic converter is usually caused by abnormal engine operation upstream of the catalyst. Events that can produce higher than normal temperatures in the catalyst are particularly suspect. For example, misfiring can cause higher than normal catalyst operating temperatures.
Retrieve and record all Continuous Memory DTCs (MIL and non-MIL).
Were any of the following Misfire Detection Monitor DTCs recorded: P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309, P0310, P0315, P0316 and P1309?
Yes No
GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the Misfire Detection Monitor DTCs. GO to HF2 .
HF2 CHECK FOR HO2S DTCS
NOTE: Incorrect HO2S signal input (such as rich/lean input signal when the engine is operating under lean/rich conditions) can cause an abnormal temperature increase in the catalyst. Refer to Section 1 , Heated Oxygen Sensor (HO2S) Monitor for possible HO2S DTCs.
Were there any HO2S DTCs (not including the initial P0420 or P0430 DTCs)?
Yes No
GO to, Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the HO2S DTCs. GO to HF3 .
HF3 CHECK FOR ECT OR CHT SENSOR DTCS
NOTE: ECT or CHT sensor DTCs can indicate that the thermostat is not operating correctly or that the engine coolant level is not filled to specification, producing above normal operating temperatures.
Were any of the following ECT or CHT sensor DTCs recorded in HF1: P0117, P0118, P0125, P0128, P1117, P1285, P1288, P1289, P1290 and P1299?
Yes No
GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the ECT or CHT sensor DTCs. GO to HF4 .
HF4 CHECK FOR ANY OTHER DTCS
Were any other DTCs recorded in HF1 (not including the initial P0420 or P0430 DTCs)?
Yes No
GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the DTCs. GO to HF5 .
HF5 CHECK REAR HO2S WIRING AND PCM CONNECTIONS
NOTE: If the electrical connections of the rear HO2S are interchanged/crossed, the Catalyst Efficiency Monitor Test will fail.
Inspect the wiring of each rear HO2S for proper routing and connection.
Disconnect the PCM, inspect for damaged or pushed out pins, corrosion and loose wires.
Are there any concerns with the HO2S wiring or the PCM connection?
Yes No
REPAIR any wiring or connection concerns. For PCM pin concerns, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). No Electronic EC root causes related to the DTCs or symptoms. GO to HF6 .
HF6 CHECK FUEL PRESSURE
WARNING: THE FUEL SYSTEM WILL REMAIN PRESSURIZED WHEN THE ENGINE IS NOT RUNNING. TO PREVENT INJURY OR FIRE, USE CAUTION WHEN WORKING ON THE FUEL SYSTEM.
NOTE: Fuel pressures above specification can produce an abnormally rich air/fuel mixture. The rich air/fuel mixture can cause higher than normal catalyst operating temperatures.
RETURN FUEL SYSTEM
Inspect the vacuum hose going to the fuel pressure regulator for proper installation and cracks. Repair as necessary.
Verify vacuum source to fuel pressure regulator.
MECHANICAL RETURNLESS FUEL SYSTEM
If applicable, inspect the vacuum hose going to the fuel rail pulse damper for proper installation and cracks. Repair as necessary.
Install fuel pressure gauge. NOTE: On Electronic Returnless Fuel System, the fuel pressure can be monitored by scan tool using the Fuel Rail Pressure (FRP) sensor PID.
Start and run the engine at idle. Record the fuel pressure.
Increase engine speed to 2500 rpm and maintain for one minute. Record the fuel pressure. GO to Pinpoint Test HC and compare fuel pressure to the Fuel Pressure Specification Chart at the beginning of the pinpoint.
Key off.
Was the fuel pressure within specifications?
Yes No
Fuel pressure is OK. If applicable, REMOVE the fuel pressure gauge. GO to HF7 . Fuel pressure is out of specification.
GO to HC4 , Fuel Delivery Systems in Section 5 for diagnosis.
HF7 CHECK FOR OBVIOUS LEAK SOURCES IN THE EXHAUST SYSTEM
NOTE: If a catalyst is in series with a leaking exhaust system, it can fail the Catalyst Efficiency Monitor test.
Inspect the following for leaks, cracks, loose connections or punctures:
Exhaust manifold.
Front exhaust pipe.
Rear exhaust pipe.
Muffler/tailpipe assembly.
Are the above components free of cracks and punctures, etc.?
Yes No
GO to HF8 . REPAIR the leak source(s). COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
HF8 CHECK FOR OBVIOUS RESTRICTIONS IN THE EXHAUST SYSTEM
A slight pressure in the exhaust system is normal, but excessive exhaust back pressure seriously affects engine operation. Causes of high exhaust back pressure are dents or obstructions in the exhaust pipe, a plugged catalytic converter or muffler.
Inspect the following for dents, areas of collapsed material and unusual bending:
Front and rear exhaust pipes.
Catalytic converter.
Muffler/tailpipe assembly.
Are the components free of dents and areas of collapsed or unusual bending or damaged?
Yes No
GO to HF9 . REPAIR the restricted component(s) as necessary. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
HF9 CHECK FOR EXCESSIVE EXHAUST BACK PRESSURE
If available install a exhaust back pressure tester and follow tool manufacturer installation and testing instructions.
NOTE: If no tester is available. GO to HF10 .
Typical exhaust back pressure (when measured near the exhaust manifold and at normal engine operating temperature) should not exceed 20.7 kPa (3 PSI) at idle and 55.2 kPa (8 PSI) at WOT under load.
Did exhaust back pressure test indicate a restriction?
Yes No
REPAIR the restricted component(s) as necessary. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3 , Symptom Charts No indications of restrictions or leaks have been detected in the exhaust system. If here because of DTCs P0420 or P0430, the catalytic converter is chemically inactive. REPLACE the catalyst that is located between the monitored H02S Sensors, only for the bank referenced, (P0420 Bank 1), (P0430 Bank 2). Do not replace any unmonitored catalyst unless it is serviced as an assembly. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3 , Symptom Charts.
HF10 CHECK MANIFOLD VACUUM FOR INDICATION OF EXCESSIVE EXHAUST SYSTEM RESTRICTION
Attach a vacuum gauge to the intake manifold vacuum source.
Monitor RPM with scan tool or tachometer.
Observe the vacuum gauge needle while completing the following:
NOTE: The vacuum gauge reading may be normal when the engine is first started and idling. However, excessive restriction in the exhaust system will cause intake manifold vacuum to decrease with the engine at a steady/constant idle speed.
Start the engine and gradually increase the engine speed to 2000 rpm with the transmission in NEUTRAL.
Decrease engine speed to base idle rpm.
Key off.
Did manifold vacuum rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes No
GO to HF11 . Manifold vacuum did not reach an acceptable level. GO to HF12 to check for excessive restriction in the exhaust system.
HF11 CHECK MANIFOLD VACUUM FOR INDICATION OF MODERATE EXHAUST SYSTEM RESTRICTION
Key on, engine idling.
Increase the engine speed gradually from base idle rpm to 2000 rpm with the transmission in NEUTRAL.
Observe the speed the vacuum gauge needle rises, while maintaining the increased engine rpm.
NOTE 1: On a non-restricted exhaust system, the vacuum gauge needle will rise quickly to the normal range as the increased rpm is maintained.
NOTE 2: On a restricted exhaust system, the vacuum gauge needle will rise slowly to the normal range as the increased rpm is maintained.
NOTE 3: The rate of speed the vacuum gauge needle rises to the normal range is slower on a restricted system than on a non-restricted system as the increased rpm is maintained.
Decrease engine speed to base idle rpm.
Key off.
Is the rate of speed that the vacuum gauge needle rises back to the normal range (above 54 kPa (16 inches-Hg)) much slower than that of a non-restricted system?
Yes No
A moderate restriction may be present. GO to HF12 . No indications of restrictions or leaks have been detected in the exhaust system. If here because of DTCs P0420 or P0430, the catalytic converter is chemically inactive. REPLACE the catalyst that is located between the monitored H02S Sensors, only for the bank referenced, (P0420 Bank 1), (P0430 Bank 2). Do not replace any unmonitored catalyst unless it is serviced as an assembly. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3 , Symptom Charts.
HF12 CHECK MANIFOLD VACUUM WITH EXHAUST MANIFOLD DISCONNECTED FOR INDICATION OF A RESTRICTION
NOTE: An intake manifold gasket leak can also cause the vacuum gauge needle to remain well below the normal range.
Disconnect exhaust system immediately after the exhaust manifold.
GO to HF10 and repeat the vacuum measurement.
Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes No
The exhaust system restriction is downstream of the exhaust manifold. RECONNECT exhaust system at exhaust manifold. GO to HF13 . A restriction is present in the exhaust manifold. INSPECT each exhaust port for casting flash/restrictions by dropping a length of chain into it (NOTE: Do not use a wire or lamp to check the ports. The restriction can be small enough for both to pass through, but large enough to cause excessive back-pressure at high engine rpm.) REPLACE the exhaust manifold if unable to remove the casting flash/restriction. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
HF13 CHECK MANIFOLD VACUUM WITH MUFFLER/TAILPIPE ASSEMBLY DISCONNECTED FOR INDICATION OF A RESTRICTION
Disconnect muffler/tailpipe assembly from the catalytic converter.
GO to HF10 to repeat the vacuum measurement.
Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes No
There is a restriction in the muffler/tailpipe assembly. REPLACE the muffler/tailpipe assembly. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ). There is a restriction in the catalytic converter. REPLACE the catalytic converter. NOTE: On vehicle applications where their is more than one catalyst, REPLACE only the damaged catalyst assembly. INSPECT the muffler to be certain converter debris has not entered. COMPLETE Catalyst Monitor OBD Drive Cycle to verify repair (Refer to Section 2, Drive Cycles ).
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hotcobra03
Active Member
frpp
Ford Racing Performance Parts [Ford Racing Parts Catalogs] i found some tips in here about high exhuast temps,,,
Ford Racing Performance Parts [Ford Racing Parts Catalogs] i found some tips in here about high exhuast temps,,,
As far as the glowing cats. I replaced the o2 sensors, adjusted the fuel pressure (it was 50+) and adjusted the base timing to 13 (with spout out). I didn't know about the pulling the spout out thing until recently, so who knows what the timing was. I would try to set it and as everyone except me knew, I couldn't. Long story short, the last 6 months or so I have been reading and reading. Trying to educate myself about my car.
I am not sure but I think all of this is what caused the cats to stop up and glow. Hopefully that problem is solved. Now I only have to find my vacuum leak.
I am not sure but I think all of this is what caused the cats to stop up and glow. Hopefully that problem is solved. Now I only have to find my vacuum leak.
hotcobra03
Active Member
long story
sounds just like my story... i just worked on mine and new jack before starting...i got a ford service manual and a predator to monitor pcm,,,and a lot of reading just like you are doing.. im waiting now for what hission50 has to say about your last reply......
sounds just like my story... i just worked on mine and new jack before starting...i got a ford service manual and a predator to monitor pcm,,,and a lot of reading just like you are doing.. im waiting now for what hission50 has to say about your last reply......
I went to the parts store at lunch. I ordered an EVR (34.99 it will be here in the AM), a pcv grommet (mine is hard as a rock), an enough vacuum line in all the different sizes to rerun ALL new lines. I will probably start on this tonight, but definately won't finish. I do want to hang out with the family sometime. It stinks that it is not warm outside yet. The wife and girls usually hang out with me while I work on it, but there is not much for them to do in the garage... Oh and I am also going to set the idle baseline. Which I had never heard about until reading some threads last night. Cross your fingers! I will update.
Okay guys. I have a small update. I replace the PCV grommet with no change to vacuum. I replaced the vacuum hose between the charcoal canister to the canister purge rv with no change in vacuum. Next I replaced the hose between the canister purge rv and the intake and the hose between the PCV and the intake. Vacuum is now at 12 not 8 and steady. I unpluged the hose going into the EGR and guess what vacuum jumped up to 14 and held steady. Tomorrow I will change out the EVR and other vacuum lines as needed and see what happens. Is it just me or is this encouraging? Am I going in the right direction?
hotcobra03
Active Member
basics
yes thats good to hear...something to really think about..engine bay temps? water? ice?your wires and hoses take abuse from mother nature and engine heat,with the work you did on the engine all of this shoud have been replaced,,or atleast checked before going back on..you can get a new vacuum harness from ford..the one for my cobra was like 70 bucks but it looks good with everything where it belongs neatlyhttp://s552.photobucket.com/albums/jj342/hotcobra03/cobra/
yes thats good to hear...something to really think about..engine bay temps? water? ice?your wires and hoses take abuse from mother nature and engine heat,with the work you did on the engine all of this shoud have been replaced,,or atleast checked before going back on..you can get a new vacuum harness from ford..the one for my cobra was like 70 bucks but it looks good with everything where it belongs neatlyhttp://s552.photobucket.com/albums/jj342/hotcobra03/cobra/
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