My 99 GTP has been having misfires lately. I've replaced the plugs and wires but still vibration when at low RPMs and I need to accel. I've read up that if it is a bad coil pack, the scanner should pull it up and tell you. I have the code P0300. Random misfire detected. I'm curious if there is a way to see if your coil packs are bad because I don't want to change them and "hope" it'll fix the problem.