I have a 2003 A6 avant code p003 55000 miles. Check engine light came on code p003 O2 sensor heater circuit left bank. I replaced the sensor with OEM part. Two weeks later the light came back on same code. Could I have received a bad sensor or do I need to look elsewhere? Does anyone know the pin out to check the heater circuit with a VOM?

Thanks in advance

Dave

 

I replaced the sensor again and cleared the CEL. After the car cooled down the code reset.

How do I check the wiring to the ECM?

Dave