O.K. y’all I need some help.I have a 2005 dodge ram with the 4.7 in it. The problem I’m having is Every 2 months or so, I have to replace either the #3 or #4 cylinder coil pack. It starts running really bad and then the CEL light comes on and I get the P0303 or P0304 code. I replace whichever one goes out and I’m good for a couple of months it’s only those 2 cylinders it’s happening on . I’m baffled and so is everyone else that I have asked about this. Anyone have any ideas that I can’t think of? Thanks

 

Have you moved the coil packs to make sure they are bad and have you check the spark plugs

 

Two issue's:
1) Cheap coils
2) No Dielectric grease used when installing. Installing them dry can cause arcing to the head and basically short circuits the coil.

 

Yes I have tried swapping them before calling them bad. That's the first thing I do.
as for the cheap coil pack thing. I got the napa gold ones. they did the same thing. If there is any better ones I can't seem to find them. The dielectric grease thing I did not know about. thanks for the responses.

 

also bad/broken wire to coil... connector dirty/damaged.
bad computer .

check ALL the easy stuff first...

 

What plugs are you using? About the only things that could blowing out coils that quickly are over voltage, or severe resistance from the plug. Either way it's going to get hot quickly and die. If you have fancy plugs, swap them out for the cheap, dependable Champion copper plugs. But I have a bad feeling this is possibly a computer/controller problem. you could also throw an extra little ground wire on the mounting bolt. It would help ensure that these two have the least resistance if that is part of the problem.