The car has an O2 sensor code. The car also won’t rev past 3000 rpm. Is the O2 sensor code related. The sensor before the cat, heater circuit failure.
Posting the actural code would be helpful It should be in the form (P0123)
I am not sure what you mean “The sensor before the cat, heater circuit failure.” Do you mean it is a code for a bad sensor reading from the first sensor?
How is everything else and how long has this been a problem?