RMcQ

I'm an allroader dropping in to tap the A62.7T brain trust. My car is throwing fault codes for both left and right pre-pre-cat oxygen sensors.

Seems straight forward. Internal resistance too high (i.e. it is broken/failed/out of spec/whatever) and it needs a new ones.

Should I just buy and replace both pre-cat O2 sensors as VAG-COM is telling me or is there any other explanation I should consider before going to the trouble. If I do buy news ones does anybody have the VW part number for the same sensor that is sold cheaper through VW?

Car is a '01 allroad. Codes do come back after being reset once car runs a while. Mileage is 61,xxx miles.

Here is the exact text:

Control Module Part Number: 4Z7 907 551
Component and/or Version: 2.7l V6/5VT G 0002
Software Coding: 06712
Work Shop Code: WSC 02325
Additional Info: WAUYP64B71N069945 AUZ7Z0Y1611845
2 Faults Found:
17539 - Oxygen (Lambda) Sensor: B2 S1: Internal Resistance too High
P1131 - 35-10 - - - Intermittent
17521 - Oxygen (Lambda) Sensor: B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent

DrHandball

This is possible. It is good practice to replace in pairs anyway.

RMcQ

that the problem was really something else. I think I am going to carefully check the wiring and connections to make sure there is no corrosion or damage that might introduce excess resistance.

After that, I'm buying some VW parts and putting them on my Audi!