Chauncey Gardner

First thanks to Dennis for the help diagnosing the O2 sensor problem. I got 2 CEL error codes
17530-B2-S2[O2 Sensor Heater Circuit,Bank2-Sensor2 Open] and 17548 Bank 2 Sensor 2 [Internal Resistance too high]. I am told I need to replace both sensors at the same time but there seem to be 2 before and 2 after the Catalyst so I dont know which I need to replace. Has anyone done this and can anyone tell me where these sensors are located on an A6 30V and if its before the Cat or after the Cat.
Also if anyone has any further insight on those error codes I would love to hear about it.
TMIA

4Driver4

If you have less than 50 or 60k on the car, I would just replace the bad one.

saabSean

Oxygen sensors are considered part of your emissions system and should be covered by your Federal Emissions warranty of 8 years/80k miles.

Chauncey Gardner

Thanks for that info. Thats probably good news to some people here since the o2 sensors are a problem I am told. My car has 101k so I am way over the limit. I priced it at the dealer who wanted 185$ for the part and 200$ labor and then bought it online at alloemaudiparts.com for 128$ and am going to attempt to install it myself. I now know much more than I ever thought I would about O2 sensors 1-4 including part numbers should anyone need them.