[johnny_quattro]

Originally Posted by steamship

I'm assuming you have a PF A8 based on the year. If so, then it only has 2 O2 sensors, which the following diagram might help locate for you.

I've only ever had the facelift model, 1999 A8 and now my 2000 A8L
I am going to make two assumptions here:

[1] My car has 4 sensors, and not two? (complete guess)
[2] This is a sensor located somewhere along the exhaust pipes?

Thanks for your response, steamship ;-)
and a merry Christmas to all.