i made the LED diagnostic light, hooked it up and periodically it will give me 4 flashes, which is suppose to indicate a faulty knock sensor/knock sensor circuit. this morning though, it gave me 6 flashes. from what i can tell from the FAQ, this means that the signal from the hall sensor on the #1 cylinder was putting out a faulty signal, is this correct? or is it the spark plug? the car does run poorly at times, sputtering and refusing to rev above a moderate rpm level, just really having no power at all, but it can be restarted several times and it will run ok. i don't get it. i've changed every sensor under the hood, except for the crank and knock sensors (they're a pain to get to). does anyone have any experience with these fault codes?