The check engine warning light on my 1996 A4 came on at the weekend. Pulled the code and checked it in my Bentley manual. Told me I have a "P0150 Bank 2 Sensor 1 Malfunction" Doesn't help a lot - is it complaining about the cat or maybe one of the oxygen sensors (if so which one)? Anyone out there who has seen this error and can interpret for me?
Thanks
Vic Norman 1996 A4 2.8 AFC engine.

If your car is a 2.8 it is the sensor on the right before the cat.It is pre-heated.If it is the 1.8 it is the one before the cat.