ok i have a 2001 audi a6 2.7t, i was wondering how many o2 sensors there are on my car. I had brought my car to autozone to check what code the check engine light was throwing out, and it was a o2 sensor. I checked the napa site and it showed there is one o2 sensor they sell, but i just wanted to see if there are different sensors for that or different plugs. Also if there was more than one, how would i know which one to replace? Help me out, this is my first audi and i switch from a honda which seemed to be easier to chang out things on. =P

 

Ha ha yeah a honda is definately easier to work on. There is a total of 4 O2 sensors in your car.
One on each bank before the cat and one on each bank after the O2 sensor.
You need to post the exact fault code number and we can tell you what sensor it is.