I do have the Bently manual on CD, but I was unable to identify which sensor with the manual. It's more difficult to navigate the CD than the real manual. I'll be buying them in print from now on.
That being said, the first couple of responses suggested the sensor before the cat, however both...
I just got my vag-com and ran it for the first time today.
(Check engine light has been on and I didn't want to go to the stealership).
Got a couple of codes I can't find anywhere.
Obviously, I have a bad oxygen sensor.
Question is - apparently there is a heated oxygen sensor before the cat...