It’s not listed in the owners manual, but according the Bosch their unheated O2 sensors (that’s what an FC uses) should be replaced every 12,000 miles. Every 4 years or 50K is probably good enough (unless the car is burning oil and/or subject to the ATF trick). To check it, warm up the engine, disconnect the O2 sensor, rev the motor in a violent fashion (is there any other fashion while testing in a garage? ) while checking the O2 sensor voltage. It should be .5V to 1.0V during acceleration and 0V to .4V during deceleration.

 

If we're talking about a fouling problem, you know you can just torch the bitch, right?





-Ted