I have an afterfire problem, can't press the gas pedal with out firing in the exhaust pipes. I have a list of things to check, and I have come to the knock sensor. I have a good one, new/unused that measures exactly 100k ohms. (positive lead in the male output, negative to the metal case surrounding it) I've measured the one on the car and got infinite resistance.

This does mean my knock sensor is bad and is most likely the source of my problem? I'm closing down for the night and I wanted a couple opinions before I douse my floor in coolant tomorrow.

Thanks..
Eric

 

Try running with the EST bypassed, or scan the ECM for knock counts while running. With the ESC inactive, there should be no retard. If the afterfire continues in EST bypass mode, the ignition timing is not likely the problem, unless it happens to be late as a result of late cam timing. Verify the base timing to be certain the cam timing has not changed.

 

OK, I'll try that...but my KS is bad right?

 

Not necessarily. A resistance test is really only a relative indication. A test with an oscilloscope would be more conclusive.