Help anybody - have 00 SSEi that has a random missfire hot - SES light flashes in dash but not had code - just says random missfire detected. Have put new Rapidfires and A/c wires on, replaced all 3 coils and tried a new ignition module. Have it a a local shop now and they have got it to do it several times. Cly 2 & 4 dropping off and cat will smell. Bring up boost thought and it will run fine. Any thoughts or suggestions?

Running good quality Premium gas? If so than might be a coil pack problem. any chance that ur plug wires are lying on the motor and possibly arching?

Change your pulgs. You don't want Platinum plugs in a supercharged engine. Get a set of autolite copper plugs. They sell for around $1.30 each. That should fix the misfire problem. If your doing any mods on the engine, consider 1 range colder on the plugs.

On an 00+, it is always a good idea to check the fuel pressure. FSM states it should be 48-52psi after 5-10 key on'* with engine off. I usually find the 00+ run light at around 40psi which can cause problems. Have them check O2'* as well, if they stay lean all the time, that'* bad. Although the pcm probably would have mentioned that by now.

Did you replace the coils with factory replacements or did you go aftermarket with MSD'* or something like that?

Used Napa coils - always run 93 or higher BP or Marathon fuel. Sometimes run 94 Sunoco. car is basically stock except K&N and syn oil

Those are actually Napa branded coils or you just got them at Napa? You may want to try a set of AC Delco factory coils. I tried MSD'* for a while and got random misfires at high RPMs. These cars seem to like there factory Coils.

Actually not sure - got them from NAPA - threw them on after it started missfiring - the shop has been working with me. They the an ign. mod at it and gave it back for me to drive. Ran out good for 4 days and then the day I was going back to square up it acted up twice. Has been there 2 weeks now as they drive it on and off.

Napa coils are good. MSD'* are known to break down and cause issues. I'm not seeing the coils, plugs or wires as an issue.

I'd be aiming for fuel, plugged exhaust, testing ICM.

What the problem with Rapid fires? I got those from my AC distributor.