Hello Scotty and forum,
I have a C200 Kompressor from 2008(w204) m271 engine.
The car has around 200.000 kilometers, it's manufactured in Germany, and so far so good, I had next to no issues with the vehicle what so ever.
My scanner reports the following error:
============1==============
P0420
Raw code: 0420
ECU: Engine control unit
Status: Test has not been completed, Validated and stored in non volatile memory, Validated fault has been present during this drive cycle
OBDII: Catalytic converter system, bank 1 - efficiency below threshold
============2==============
P0420
Raw code: 0420
ECU: Engine control unit
Status: Pending
OBDII: Catalytic converter system, bank 1 - efficiency below threshold
============3==============
P0420
Raw code: 0420
ECU: Engine control unit
Status: Confirmed
OBDII: Catalytic converter system, bank 1 - efficiency below threshold
Should I go ahead and replace the O2 sensor in bank 1 before the catalyst, or is there a good known way to verify if it's just a faulty sensor, a leak on the exhaust somewhere, or a bad catalyst?
Thank You.
It means you catalytic converter is working at below 95% efficiency often it means you need a new Cadillac converter but realize they go bad for other reasons so if a converter goes bad it could be because engine is burning oil and clogging it up or running to richer lean and burning it out
