[jyount]

sounds like injectors to me. You need to hook it up to a scanner and tourqe it up in the driveway. Ie foot one the brake and the gas at the same time. It loads the engine to simulate conditions without having to drive it. You should see the miss in real time, it may not be missing bad enough to through a code. FIRST swap coils and see if the miss follows the coils, it is way to easy to not do it first. Next you can do the same with injectors, they aren't that hard to swap either. If the coils in injectors are bad you cannot fix em. If they are plugged up, fuel injector cleaner isn't going to help either. I have bought a reconditioned set off ebay from "fuelinjectionconnection" user before for around 100 bucks for the whole set of 8. They worked great, so he has good stuff. If you have any intentions of camming it or anything in the future get some higher lb/hr ones while you are at it. The coils are not uncommon on this family of engines either. If you swapped out a blown one do you have the old for parts? If so, you got cheap parts sitting around.