saveth ... 1/17/2020
2010 Audi S5 Base 8 Cyl 4.20L
Intermittent O2 sensor codes... have they gone bad? (4.2L V8- 105,000 miles)
i have had occasional fault codes of P2098, P2096, P2196, P2198, and the even more occasional P0161/0141 (O2 sensor heating circuit malfunction) which are all codes for too much O2 in the exhaust. I have been monitoring the situation with an OBDII scanner for months and sometimes I can go multiple weeks with no problems. Other times, it's every other day that these codes come back. To mitigate these issues, I have replaced a fuel injector (that was causing a misfire) and only run Shell Nitro+ gas through the car, I carbon cleaned the engine, checked all my vaccuum lines and replaced them all, and replaced a fuel valve to correct a preexisting P0171 (that has not reappeared). I also had my cats replaced at a dealership (yuck) in accordance with the recall.
Please note that none of these DTC fault codes describe simply replacing one or more of the O2 sensors.