Pulled the codes, help.

TheDamned

"I am Canadian and Damned for it!"
Jul 22, 2003
457
0
48
Montréal, Québec, Canada
Just to help you guys, I have stock exhaust system except a MAC O/R H-pipe, the 02 sensors were installed with the h-pipe. Also, I have a steady idle at ~800rpm.

Now, few questions.

I got these:

172: HO2S sensor fault/not switching, or fuel system at adaptive limits.

176: HO2S sensor fault/always lean.

181: Fuel system at rich adaptive limit at partial throttle / systeam lean.

Are these ALL related to the 02 sensors malfunctioning because of the nonexistence of the cats ? Is this why my car ALWAYS smell gaz and I got tons of back fires, my MPG sucks aswell, is it because i'm running too lean ? If yes, what's the cheapest\best way to fix this issue ?

189: Same as the above.

332: Insufficient EGR flow detected.

Is th EGR faulty because of the infamous H-pipe or it's different ? Do I need to replace it ?
Also, if that can help you guys, sometimes, like when I don't use the Stang for a week, once I start it and I WOT soon after starting it, it completely lacks of power, it skips like hell and then it picks up and goes normal.

Thanks gear heads.
 
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there are 3 colored hardlines.
ones tan,the other green,and the last red.(i think)
they are wraped in a black loom coming out of the pass side fender,near the mass air connector.
remove the air intake tube to get to them.
one goes to the egr valve,the other,a valve below the alt,and the other to the vac fitting on the upper intake.(i think)
i replaced the broken sections with rubber vac lines.

here are some pics i took to give you an idea of their locations.sorry,i dont have anything with more detail.
hope this helps ya out a little.
:SNSign:

egrvalve.jpg

egrvalve2.jpg

egrvalve3.jpg
 
Ok guys,

I pulled out my EGR module today to see what's up.
Thing is, I broke the pipe that goes from the headers to the intake... it was rusty as hell and it broke when I was trying to unbolt it off. Anyway, check the EGR and the tubes were pretty much clear, some carbon by the sides but it looks like it was working properly... Checked the little cylinder and it looks to be working well. I checked the vaccum line connected to the EGR, is this vaccum supposed to always be sucking air or it does only when the CPU tells the EGR to open the valve ? Since the EGR valve looks clean the only two issues I see to cause the 332 code would be the pipe from headers to intake that was cracked (rust) and air was coming out OR the vaccum is just not working ?

What do you guys think ?
Thanks
 
I checked the vaccum line connected to the EGR, is this vaccum supposed to always be sucking air or it does only when the CPU tells the EGR to open the valve ?

It's only got vacuum at cruise. If it sucks your finger in at idle, you have either a misrouted vac line or a stuck EGR solenoid. This would cause the car to idle poorly or not at all, depending upon mods and how much the EGR valve is opening. If this happens, it should throw an EGR position sensor code, but you never know......
 
If the EGR was faulty it would probably be from the diaphram being opened or closed at the wrong time. I would think, however, this conditon would cause a CEL. Maybe not a solid CEL, but it would probably flash.

Hey man,
The error code is 332 "Insufficient flow"... I mean I took off the EGR valve and how i'm supposed to know if teh diaphram is working ? That thing is INSIDE the EGR, I tried to blow\suck air (with my mouth) in the vaccum hole and it didn't do much. The pipes looked pretty clean to me, what's the best way to test teh diaphram ?

It's only got vacuum at cruise. If it sucks your finger in at idle, you have either a misrouted vac line or a stuck EGR solenoid. This would cause the car to idle poorly or not at all, depending upon mods and how much the EGR valve is opening. If this happens, it should throw an EGR position sensor code, but you never know......

Hi hissin,

I have no problem with my idle at all, it wasn't sucking my finger when I checked it but then again I was at idle. What you're telling me is that the EGR sends a signal to the CPU and the CPU puts the vaccum that goes to the EGR active (in sucking) mode at cruise ?

Thanks

Also, some guys told me the EGR is useless because I have no cats (off road h-pipe), is it true ?
 
The EGR system and cats are mostly unrelated. The guy was probably thinking of the Smog pump being useless if you don't have cats.

If you let the car idle and apply about 6" of vacuum to your egr valve, the car should idle really poorly or stall. This tells you that it probably is capable of functioning ok (in lieu of being able to examine the diaphragm). Also , when you pull a vac on the EGR valve, you can watch the diaphragm move. It doesn't move a lot but it's also not a little. If you have doubts, see if a parts store sells an EGR valve and go compare the movement of that diaphragm vs yours.

The CPU sends a signal to the EGR solenoid when it wants the EGR open. The EGR position sensor is what tells the EEC how far the valve is open.
 
The EGR system and cats are mostly unrelated. The guy was probably thinking of the Smog pump being useless if you don't have cats.

If you let the car idle and apply about 6" of vacuum to your egr valve, the car should idle really poorly or stall. This tells you that it probably is capable of functioning ok (in lieu of being able to examine the diaphragm). Also , when you pull a vac on the EGR valve, you can watch the diaphragm move. It doesn't move a lot but it's also not a little. If you have doubts, see if a parts store sells an EGR valve and go compare the movement of that diaphragm vs yours.

The CPU sends a signal to the EGR solenoid when it wants the EGR open. The EGR position sensor is what tells the EEC how far the valve is open.
Thanks alot Sir.

Ummm I think I pulled the vaccum out and the idle didn't change, would that mean that my EGR Valve is either stuck open or closed ?
I'll re-try this.
 
Thanks alot Sir.

Ummm I think I pulled the vaccum out and the idle didn't change, would that mean that my EGR Valve is either stuck open or closed ?
I'll re-try this.

I'm not sure what you mean by pulled the vacuum out. At idle, there is no vac in the vac line to the EGR. You can pull it on and off and nothing happens. If you pulled it off and the idle got better, then you'd have an issue. Or if you pull it off and put another line on and apply your own vacuum to this line (using a vac pump or one's mouth), the idle should get crappy. If it doesn't, there's an issue.

The bottom line is that the EGR does not function at idle (nor should it) and if it does function, it makes your idle worse. Knowing that, you can see the logic of the testing.
 
The bottom line is that the EGR does not function at idle (nor should it) and if it does function, it makes your idle worse. Knowing that, you can see the logic of the testing.

Following that logic my EGR is working A-1 then since I have NO idle problems at all but I still have the EGR Insufficient flow code. I'm gonna order a new pipe (the ones that goes from the header to the intake) that was previously leaking, maybe that's what causing the problem, i'll keep you (and other people reading this) updated.

Thanks alot.
 
With the insufficent flow code, also check your position sensor.

KOEO: put your DMM on the position sensor signal wire and note the reading (it should be under 0.60V). Then slowly open the EGR valve (using a vac pump or whatever). The reading should go up. If it doesn't, pull the position sensor and bench test it. It might have crapped itself on you.
 
With the insufficent flow code, also check your position sensor.

KOEO: put your DMM on the position sensor signal wire and note the reading (it should be under 0.60V). Then slowly open the EGR valve (using a vac pump or whatever). The reading should go up. If it doesn't, pull the position sensor and bench test it. It might have crapped itself on you.

Hi Hissin,

Thanks for your prompt replies.
Is there any "test" pins available for the sensor signal on the EGR ?
I don't see how I can test the sensor signal when the EGR is functioning and plugged... I'm in electrical engineering so I know how to take voltages readings BUT i would've to litteraly cut one of the wire and attach a parallel wire to it to test it... i'm not sure that makes sense.

I DID test the small piston in the EGR unit since it's like a variable resistance, I moved the cylinder up and down and the resistance was changing so the small piston is working well .
 
You could rig up an intermediate harness that goes between the disconnected stock connectors. The intermediate harness can then be probed without harming your stock harness.

Or use your DMM's self-peircing leads. A safety pin or dental pick also can work. Silicone (anaerobically seal) any breaks in the wire when done.