I picked my '06 RX8 up from the dealer yesterday after getting a new engine from the compression test thingumabob. I cranked the car to leave and the Service Engine light comes on. I call the service tech out to the car, he drives it back and they said that it's an O2 sensor bad.

My question is this, can I first try running some injector claner through it and reseating the code by unhooking my battery and seeing if that clears up the problem before replacing the sensor? If not, how many O2 sensors does my car have in case I end up replacing it?

 

There are two.
The front one is very important because it helps to set the Air Fuel Ratio in the closed loop engine control.
A bad front sensor will make your car run badly, could destroy your cat and eventually your engine.

The rear one only checks the cat so it can be ignored for a period of time.

Please get the trouble code associated with the CEL

 

Actually the cars running excellent. They replaced the motor mounts as well so it's running smooth with no vibration. Maybe it's safe to say it's the rear one then. Where is it located?

 

On the cat

 

Can some one tell me exactly where the front one is. Its showing to be the front bank/heater sensor?