My O2 Sensor went bad on my 1988 RX7, but my check engine light didn't come on? Is this a common thing for RX7 owners?

 

on mine the minute the O2 sensor was acting up the engine light came on. It went off again because it wasn't quite shot. (89 Turbo II)

Either your O2 sensor wasn't bad, or the light in the light cluster is burnt out....you might want to try disconnecting the O2 sensor while the car is running, it should change idel a bit and the check engine light should come on (it might go off again, but check the engine error codes).

 

I did, I drove the car with the 02 sensor off...no no check engine light....is it possible to fix the light cluster?

 

S4 ECUs are very primitive. I doubt a bad (out of range) O2 sensor would cause a check engine light.

 

well if the s4 is that primitive then maybe it is time to whip out the good old multimeter.

Check the signal Voltage from the O2 sensor...it should read somewhere between .98 and 1.1 V at idle.