Just wondering, my Smog pump must be going out and it has been throwing the "secondary air injection" code for several days. I dont really notice any difference in performance, but I know certain codes will make the car go full rich to protect the motor.

 

I have not read anything that says that codes causes a "limp".

 

The PCM has a variety of ways to respond to an SES light or a code. For example, if you lose the MAF sensor (94-97), it simply defaults to speed-density programming. If you lose the high resolution pulse from the Otpi, the PCM uses the slightly less precise info available from the low resolution pulse. When most sensors are "lost" there is a default that provides limited info that simulates the missing sensor. Some performance or driveability loss may be noticed. True "limp home" is really just enough to keep the engine running with virtually no inputs other than the throttle. I doubt that many people have actually experienced true "limp home".

Since the AIR system only operates for a few minutes at startup, it is likely that the PCM does not take any corrective action after that short period of time, except turn the coolant fans on.

 

thanks, thats what I wanted to know