I've had a few CEL activations since I bought my 2009 C2 PDK, which haven't resurrected since I swapped the gas cap. I have however, a set of error codes left that I'm trying to resolve on Bank 2
P2198 Oxygen sensor ahead of catalyst convertor BANK 2 - too rich signal
P2A04 Mixture behind catalyst convertor. BANK 2. Implausible.
My gut reaction was 'Change the sensors', but thinking about it I'm wondering if something else is underlying. As the sensors are returning a signal, I'm wondering if it is something upstream that is causing the issue?
Has anyone seen these codes together and have you any suggestions? Many thanks