98 lumina service engine light problem

[tudstuen]

i had it checked and code said egr -replace. i did and after a few days the light came back on. took it back now they say it needs intake manifold cleaned. idid and still the light comes on. Any help offered. it has 73 k .. what about O2 sen.? or other. i disconnected the positive bat. cable but it would not re-set. do you have to take off neg. also? the casr runs fine no problems at all.

[richtazz]

what engine do you have in your car? IF it's a 3.8, the problem could be the o-ring seals in the PCV housing causing your egr code. I know it sounds bizarre, but it's a possibility. As far as clearing the codes, you have to use a scan tool, the old diconnecting the battery trick doesn't work on OBDII cars.

[maxwedge]

Richtazz, re: o ring in pcv area, the pcm, I believe, judges the operation of the egr by a slight drop in vacuum as it operates, the leak in that area must skew the map readings and fool the pcm into thinking the egr is not working as programmed. Vehicles with only a maf use the the maf inputs to do about the same thing.

[tudstuen]

Originally Posted by tudstuen

i had it checked and code said egr -replace. i did and after a few days the light came back on. took it back now they say it needs intake manifold cleaned. idid and still the light comes on. Any help offered. it has 73 k .. what about O2 sen.? or other. i disconnected the positive bat. cable but it would not re-set. do you have to take off neg. also? the casr runs fine no problems at all.

If it is the o ring how do you fix the problem?

[richtazz]

GM offers a PCV repair kit if your o-ring is ripped or damaged. The kit comes with the new PCV valve, both lower and upper o-rings, the PCV retainer spring, and the plastic cover the MAP sensor clips into, the part # is 89017274

[tudstuen]

Thanks for the quick info. my engine is the 3100 does that matter or could it still be the pcv? I had it replace within the past year but i think it was just the valve. Anyway i hate taking cars to dealers specialy when they really dont fix it.. They just said well thats what the codes read.Looking back i will bet the egr wasnt bad.
Thanks

[maxwedge]

This advice applies to the 3800, you need to post the engine always when you ask a question, everyone spent this time /advice for the wrong engine!!

[tudstuen]

Originally Posted by maxwedge

This advice applies to the 3800, you need to post the engine always when you ask a question, everyone spent this time /advice for the wrong engine!!

Sorry you wasted your time. I am new to this and very frustrated with GM dealers that cant fix the problem. But really how much time was it!! Maybe this is a dumb question but why wouldnt it be simular in the problem. They work the same. Thanks

[maxwedge]

The pcv sytem on the 2 engines are completely different the 3.8 we were referencing is set up in the engine in such a way it affects hte map if not sealed, the 3.1 is designed differently.

[tudstuen]

Originally Posted by maxwedge

The pcv sytem on the 2 engines are completely different the 3.8 we were referencing is set up in the engine in such a way it affects hte map if not sealed, the 3.1 is designed differently.

Thanks again but any idea what it might be. Ill try anything. Ive replaced the gas cap also. Other then that all I can think of is just drive it and see what happens. Like I said the car runs fine. I know alot of folks wouldnt care about it but Ive always tryed to keep my cars in good repair.Its pretty sad when GM mec. cant repair something they diagnosed.