I recently bought a 97 A4 2.8 Quattro with 129,000 mi. The ac was blowing warm and my local mechanic said the compressor was bad. He put in a used compressor and its working fine. However, when I first ran the car after the change, the CEL came on and then the coolant light started flashing. They put more fluid in and the coolant light stopped. The CEL remains and mechanic says its a bad front O2 sensor. Autozone confirmed it is P1106 code and said it was likely a heated O2 sensor.Why would changing compressor trigger the O2 sensor code?Any ideas on this one?

 

It wouldn't - Your O2 sensors are probably old.

 

Just timing, since AC didnt work before it wasnt getting warm, now its getting real warm so O2 went to hell, change it out car is old its 100 bucks and labor

 

By saying "the cell still remains" do you mean that they cleared the codes and it came back? But, ^ yeah - the systems are seperate and the ac change didn't cause this fault, was just its time.

 

Yeah. He's cleared the codes twice and its come back. I'll replace the sensor and hopefully that will take care of it.

Thanks for the responses and btw, I'm lovin' the A4. Looking through this forum has been a big help too.

 

Are there 4 sensors, 2 front and 2 rear? Or just 1 front and 1 rear? Also, can I get by just replacing the faulty one sending the code or is it best to replace all at same time?