O2 sensor question
 

Hey, guys. I am back from a short absents from the boards. Brief stint there with no Camaro in the garage. Yes, I suffered withdraws. I never have posted much, but I do appreciate the wealth of information on the boards. I have read up on previous post on O2 sensor troubles and I want to confirm my suspicions before throwing money at it.

The car is 00 SS A4, all stock for now, with 78K on the ticker. I got what I felt was a deal on the car, and I knew about the codes before the purchase, but now I need to resolve the problems. Getting codes; P0137 (Bank 1, sensor 2, low voltage), P0157 (Bank 2, sensor 2, low voltage, P1161 (Bank 2, sensor 2, heater control), P0161 (Bank 2, sensor 2, Heater Performance). I have abbreviated the descriptions, but you get the idea.

I had him take it to the dealer pull the codes before it was picked up, and of course they reset them. I drove the car 250miles home, with no codes. I took it easy the first 150miles, but tested it out on the last 100miles. No codes . 2 days later drove 15 miles, took it easy for the most part. Then I took off from a stop, got to about 5500 and the SES light came on. Slowed down, light is still on but drives like it always has.

Question: Should I just replace the two rear o2 sensors and reset the codes? Could there be another problem here?

Thanks for your help, I hope there is enough information here for you to go on.

The P0137 looks like an oddball, all the other codes Bank 2 sensor 2 type failures ( pass side , after the CAT) point to the O2 sensor OR a cable problem. Check for bad connection, burnt wires, then I'd replace the O2 and monitor the P0137. None of these effect performance the rear O2's are there to check for correct CAT operation required by OBD2 standards.

Thanks for the reply. That is the direction I was headed, I hope your right bank 1 could be fine. I will check the wire and then look at replacing just the rear bank 2 sensor to start.

Are you sure someone didn't try to eliminate the after-cat O2 sensors, or install a set of O2 "sims" that went bad?

When the light came on at "about 5500" (rpm???) did you check to see if it was still due to the same O2 sensor codes?