I'm having a problem with my 97 TJ 4 cylinder. It will miss on one cylinder. It first started having problems on cylinder four, and then it switched to cylinder one. I've swapped plugs on cylinder four , and had a brief repair (about 10 miles) and then the problem returned. I put in a new cap and rotor, and switched out the PCM. I also unplugged the up stream o2 sensor still no luck! It always misfires no matter the speed! I also put cleaner through fuel injectors! Any suggestions?