I reicevied code PO 300 RANDOM MULTIPLE CYLINDER MISFIRE. I AM NOT SURE WHERE TO START WITH THIS BECUAUSE THIS IS PROBLABLE CAUSE FOR AN OPTISPARK AND THIS HAPPENED ALL OF A SUDDEN SO I AM WILLING TO BET THAT THE WIRES AND PLUGS ARE NOT THE CAUSE. The other option would be the ignition coil but i would think that I would not be able to drive my car at all so anybody have any experince with this.