310ALLROADER

The 2 fault codes I am getting are:

Address 01: Engine
Controller: 4Z7 907 551 K

17539-Oxygen (Lambda) Sensor, B2 S1: Internal Resistance too high-P1131-35-10- Intermittent
17521-Oxygen (Lambda) Sensor, B1 S1: Internal Resistance too high-P1131-35-10- Intermittent
Readiness: 0010 0000

The check engine light has come on and then gone out on its own three times, and even after resetting and clearing with Vagcom, the CEL is still coming back on. Brought car to the dealer thinking they would replace O2 sensors on extended warranty, but they say the codeds are likley due to my aftermarket Forge diverter valves. Does this make any sense or are they just trying to avoid the O2 replacement???

quickaudi:STFA

Just a guess, but sounds like they are blowing you off. Def. need to replace O2 sensors.

DrHandball

2nd, the DVs have nothing to do with the internal resistance of an O2 sensor.

CorradoG60

If the DVs where bad, it would show a fault for recirc. valve. You want to see what the activity is registering on the O2 sensors.