I have a similar problem when I step on it a bit my check engine light comes on and stays on till I turn the car off and back on it goes away, pulled codes today and got a code 52 knock sensor signal. I have a couple extra knock sensors laying around if that is what it means that a sensor is bad, or does it actually mean the wires connecting the knock sensor to the ecu are fubared? Didn't want to highjack the other guys thread.