Hello Everyone,

I'm new to the Audi Cars and never owned one. I have traded my 2004 Dodge SRT4 to get one of these Amazing Machines. 2001 Audi A6 4.2Q. I have an Check Engine light that just came ON and I was wondering which o2 Sensor do i need to change. I know there is 4 O2 Sensor on these cars and don't know which one to replace. PLEASE HELP! Much appreciated guys!

here is the Engine Code P0172:


and here is a pic of my 2001 Audi A6 Quattro 4.2

 

Bank 1 is the passenger side (where cylinder 1 is located), so that'd be the passenger side pre-cat O2. Car looks great and you definitely picked the right engine. Congrats

 

The scanner is showing 4 codes - what are the others?

 

That fault code is for a rich condition! You will have to find out what is causing it to run rich. Remember the o/2 sensors are just the messengers of the fuel mixture. Why are you looking at replacing the o/2 sensor?

What are the other codes?