"Check Engine" Warning Light

My 1995 Legacy "Check Engine" warning light went on today. I would like to know all the possible malfunctions that are covered by this warning. This happened once before and a faujlty "knock sensor" was the culprit. Fortunately, the car was still under warranty and the fix cost me nothing. I don't want to pay for a faulty knock sensor. I think I can hear it if the engine starts knocking. (It never did - still purrs like a new car.) Any suggestions? mbardash[/list]

You have OBDII on that and have to scan it to get the code. I don't think it can be read with the underdash connectors like the OBDI cars. The knock sensor is supposed to work before you hear it knock - once you hear it the damage may already be done. It's basically a microphone that detects the sound of predetonation and signals the ECU to cut timing back to prevent it from getting to the full-on knock stage. It is possible that other things can cause an oversensitive knock sensor to think there's detonation happeneing when its not. Why do you suspect the knock sensor? The CEL can mean anything from an individual injector problem to an O2 sensor and anything between. Steve

Is there an autozone in the area? They pull codes for free. The 95+ legacy is obd II, the 94 and below are all obd I, You would be able to notice if the knock sensor was bad, as mentioned timing would be retarded, and the fuel map would be cut as well. The car would be very very bogy. There are tons of things that a cel can mean.

Check the gas cap and see if it's tight...the easiest CEL to troubleshoot. If it doesn't go off after a few minutes or less...then Autozone, Schucks etc.. can pull codes. //M