misfire under load (please Help)

[NiCeBiRd6]

i went to the dealership and they said nothing was wrong, typical. I went back a few weeks later to take a tech for a drive. he hooded up a computer in the obdII port. I had no ses light but it was reading a cylinder 4 misfire. Its twice as bad when the a/c is on.Since then i had the wires, fuel filter, plugs, and injector replaced. They also moved the coil packs around. I went back to the dealership and they said i was running up a bill. I have 3 months left on warranty and until i settle this problem with the dealership, does anybody have any suggestions of what might be wrong. This topic has been discussed before but there had been no solid answers. thank you.

[RAR]

I had the exact same problem in my 3.4, the coil packs tested ok, but that ended up being the problem.

Mine would only do it when the car was warm.

I would suggest replacing the coil packs a - it may be only one, but do all 3 because it is under warnenty.

I only replaced the one closest to the engine and that was the one that caused the problem.

good luck

[ka50]

I have the same exact problem right now. Stumbles under load, pulled codes - cyl 5 misfire. Going to replace plug, wire, and see whats up...