86 Sensor Light ??

[Yinzer]

I've searched around and can't find the answer. 

 

 What Sensor is this light for ? Early style Check Engine Light ?

 

 How do you read the Code...if there is one ?

[Yinzer]

Anybody ?

[Yinzer]

12 minutes ago, Yinzer said:

Anybody ?

 

[datzenmike]

I only have the '84 FSM but it does also show a sensor and I traced it to a warning to check the O² sensor. This would only apply to later California feedback carburetors or the later after  April '85 trucks with the Z24i (EFI) which also had an O² sensor.

 

I would try disconnecting the battery for 30 seconds to reset all codes and such and see if the light goes out. If it does.... fine. I if doesn't or it comes on later there must be some reason. Try running a dedicated ground from the exhaust manifold to the block to solidly ground the 0² . Check the coaxial cable to the O² isn't damaged. Last, replace the O². Without the O² the EFI will go into limp home mode and to prevent an accidental and damaging over lean it will default to an over rich condition and give very poor gas mileage.