Got a P0137 code yesterday. I did a little reading up on old threads and learned that its related to heated oxygen sensor on B1S2. Being this a model with 3 sensors 98+. It would make it the sensor after the cat. I erased the code and will wait and see if it comes back. Meanwhile I am looking at a replacement. What do you guys prefer brand wise, I cant seem to locate a GM part. And I dont know if Denso or AC delco is the actual OEM manufacture. I see Bosh as another option.

 

Are you able to graph the 3 O2 sensors so we can see what that post cat guy is doing relative to the other 2?

I would get the Delphi or GM version at Rock Auto.

George

 

Ok the Scanner said I have low voltage circuit. But I will try to graph it sometime today.

 

Just keep in mind that that error code says you have a circuit problem not necessarily an O2 sensor problem. It’s your call as to whether you want to replace the sensor before doing some diagnostics to rule out power, wiring, the cat or other causes of the problem.

George

 

Good point. I will hold off on buying the part. I did notice a small vacuum leak near the check valve and reservoir. I will address this first.

 

Given your vacuum leak, lets also generate all 4 fuel trim numbers at idle and 2500, both in park.

George

 

dumb question, before I fix the vacuum leak or after?

 

Before so that we have baseline data before we start changing things.

George

 

ok, so I was not able to get in-depth readings on the sensor. I only got basic voltage reading graph. I noticed the sensor seemed to be off or dropping out time to time. Could this be what's tripping the code. I went ahead and deleted the codes and 90 miles later not code re-appear. Will continue monitoring check engine.

 

Does your scanner offer STFT B1, LTFT B1, STFT B2, LTFT B2?

George