02 sensors bad every 6 months or so..

[Raginstang]

alright... im getting tired of chagning them cause it is getting expensive at 40 dollars each every few months... I have codes

41
91
33
13

I don't have cats and I have the stock fuel pump.. what is the deal? my mods are listed below.. howecome I keep eating them? I don't have my egr plugged in right now and that is the code 33.

 

[speadfreak]

just a stab here...........some race gas will ruin you O2 sensors.

 

[joel5.0]

Reads like you may be replacing good O2 sensors...the possible causes for codes 41/91 besides the sensors themselves are:
- Fuel Injectors
- AIR system
- PCV/Hose
- Unmetered air leak between MAF and TB
- Vacuum leaks
- CANP
- Fuel contamination

Code 13 is of interest here, possible causes for it are:
- Throttle linkage binding
- Throttle plates open
- Improper Ign timing
- IAC/TB contamination
- IAC circuit short to ground, faulty IAC
- Vacuum leaks
- PCV system sealing
- Improper idle set

Causes in common for both codes

Aside from the obvious check for vacuum leaks suggestion....do you have a breather on the RH side valve cover?....is the breather hose to the TB open, connected or plugged?...LUK

 

[Raginstang]

thanks for the replies.. um... no I am not running race gas. I only use 91 octane..(highest availiable in CA) and no I don't have a breather on the right side. im running stock valve covers with the stock hose to the TB. I may have a bad IAC.. Im not really concearned about that as much as the other codes right now. I can feel the car running poorly only at low rpms, especially on take off. sounds like its missing real bad at low rpms, and smells real rich and is blowing lots of blue smoke out...

 

[joel5.0]

Blue smoke = burning oil = contamination of O2s

Have you changed the PCV mesh screen filter underneath the valve, if it's clogged, it could cause the smoke problem you're having.
For the missing problem, a cylinder balance self-test would help to id which one(s)have a problem. My 2¢.

 

[bill302]

are you loosing any coolant a small amount of coolant in the exhaust from a leaking intake gasket or head gasket allowing antifreeze into combustion chamber and out exhaust will cause o2 sensors to go bad..... just a guess if not mark that off the list..goodluck.

 

[Raginstang]

hey, thanks again for the replies.. umm.. the coolant thing might be right on for this particular time. I just replace the lower intake manifold gaskets cause it was leaking at the front of the block. and I may of had coolant in the cylinders when I fist fired it up, from when I pulled the manifold off. but I still had to replace them a lot before.

 

[JimBowy]

hey, thanks again for the replies.. umm.. the coolant thing might be right on for this particular time. I just replace the lower intake manifold gaskets cause it was leaking at the front of the block. and I may of had coolant in the cylinders when I fist fired it up, from when I pulled the manifold off. but I still had to replace them a lot before.

you said the o2 sensors have been going bad.... how have you been determining they are going bad?

 

[Raginstang]

well, for one.. I have a/f ratio guages in my cockpit and they do not switch like they are suppose too.. secondly I use a voltmeter to check them.

 

[JimBowy]

well, for one.. I have a/f ratio guages in my cockpit and they do not switch like they are suppose too.. secondly I use a voltmeter to check them.

have you tested them before installing them? can you monitor their progress and see them getting progressively worse?

your not giving us much to go on

 

[Raginstang]

no, I cant say that I can progressivly monitor them from new to bad. but like I said, I can see if they are switching or not with the a/f guages, which all they really do is show the 02 switching in a wave graph. all Im asking is howecome I keep getting these codes for the 02 sensors.. I just replaced the lower intake manifold gaskets and am 100% sure there is no vacuum leak from there.. also, like I said, it for some reason has excessive blue smoke coming from the exhaust all of the sudden. not there before the gasket replacement. could they be going bad because im running too rich?

 

[JimBowy]

no, I cant say that I can progressivly monitor them from new to bad. but like I said, I can see if they are switching or not with the a/f guages, which all they really do is show the 02 switching in a wave graph. all Im asking is howecome I keep getting these codes for the 02 sensors.. I just replaced the lower intake manifold gaskets and am 100% sure there is no vacuum leak from there.. also, like I said, it for some reason has excessive blue smoke coming from the exhaust all of the sudden. not there before the gasket replacement. could they be going bad because im running too rich?

blue smoke shouldn't be related to your o2 problems directly.... blue smoke would indicate oil (as already mentioned) so I think you need to continue looking for other sources of problems...

how many sets of o2 sensors have you gone through?

 

[jrichker]

Something else to check - The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts

 

[Raginstang]

thanks for the replies.. I have a good set of o2's laying around I will see if that helps first..

 

[Raginstang]

well, i just installed the old 02 sensors and its still the same... I cant see why it is like this after the intake repairs!! I also recently adjusted the valves.. which I guess could be doing it if I messed them up. they are a little noisy and could be the cause of the oil burning?

 

[joel5.0]

well, i just installed the old 02 sensors and its still the same... I cant see why it is like this after the intake repairs!! I also recently adjusted the valves.. which I guess could be doing it if I messed them up. they are a little noisy and could be the cause of the oil burning?

That would explain a lot.....were the symptoms there before the intake repairs and the valves cal?...LUK

 

[Raginstang]

no, it didn't burn the oil and run like this before the intake work. but the valves have always been noisy. it sounds like one or more is slapping on the drivers side. maybe staying open and letting oil through? also, maybe causing the off idle sluggish performish?

 

[rockyracoon]

if ur not gtting into open loop your a/f will not bounce at idle from lean to rich as would normally,you should check
that gnd orange wire for the o2s that jricher referred to.

 

[Raginstang]

when im at idle it is indicating lean at idle.. but when I punch it the go straight to rich.. which woul indicate they are working??

 

[joel5.0]

no, it didn't burn the oil and run like this before the intake work. but the valves have always been noisy. it sounds like one or more is slapping on the drivers side. maybe staying open and letting oil through? also, maybe causing the off idle sluggish performish?

I suggest you revisit your valve train, the noise, missing symptom you mentioned, smoke....all have a bearing in A/F control, not just the EEC-IV and components...they can compensate, but within their limits. A tune under such conditions would be a tune with limitations also.

Probably need to check pushrod lengths, lifters might need replacement, valve seals alright?........have you done a cylinder compression check?...an engine vacuum test?...those results would give us some clues. LUK