I'm not going to go into great detail about this problem. If you know anything about cars you can follow along. P0300 code 1 and 4 plugs black soot, not firing. 2 and 3 plugs tan ash firing nice. Car idles and runs like crap, no power, etc, same issues you've heard before. Here is the fun stuff. I pulled number 1 plug wire off while running and the motor evened out. Plug it back in and the car runs great. So there is an issue here somewhere. This has happened twice. I need to diagnose this problem before I will let my daughter drive it again. Ideas. All the usual test and checks I have done. Missing something.