Contour Enthusiasts Group Archives Forums General Troubleshooting O2 sensor codes

Here are the two O2 sensor codes my car is giving:
P1151
P1131

Are these both prior to the CAT?

Thanks,
Jason

those are indicating both upstream O2s are lean.

The odds that BOTH are bad are slim.. instead, I would suspect that they are working perfectly, and indicating what you truly have... a lean condition in the engine.

Look for intake leaks around the TB, UIM/LIM, IAC and EGR.

Vacuum leaks (green vacuum tube on top of the EGR, for example) can cause lean conditions, as well.. any air entering the engine after the maf is unaccounted for and will make you have that condition.

Spraying carb starter spray in a few specific areas will test for cracks, or holes in hoses/gaskets/etc. The spray is sucked in and causes the engine to stumble, indicating a lean condition. (obviously, avoid the intake filter, as that would provided you with a false positive in that area)

Exhaust leaks right at, or near, the upper O2's can do the same thing.


Ray

Ray,
Thanks for the input. I'll try to find a leak.

BTW, the CEL comes on intermittently. Right now it's on, but for the last 100 miles or so, it had gone off temporarilly. Do you think that still sounds like a vacuum leak?

Thx,
Jason

i JUST had the P1131 code, and mine came on and off as well....knock on wood but i fixed it....what i did was took off my MAF, cleaned it with electrical contact cleaner, then repositioned my IAT sensor, checked my vaccum lines and then reset the pcm and its been off for a few days now....KNOCK ON WOOD!!!!!