I have a 99 grand prix GTP. I have a P0300 code. (Random multiple cylinder misfire) This code has been coming on maybe once every couple of months. I just kept clearing it because it barely misfired and didn't cause a problem. A couple days ago I was getting on the gas pretty good and then the P0300 code came back. Now while driving normally the car runs fine, but under a load or at WOT the car mifires badly. My coils are new, my plugs are new and my wires are new. None of the wires are burned either. I checked my fuel pressure and that is fine as well. I tried a new ignition module and that isn't it either. Its starting to mis when I start it up and then a little bit at an idle. Any help would be GREATLY greatly appreciated. Thanks,