Hey guys could really use some help I have a 99 wj with the 4.0 and It tells me I have a misfire on cylinders 3&4 and It has a really hesitation or vibration when idleing what could the problem be.
P.s. I also replaced the spark plugs and the coil pack and I had to rewire the cylinder 4 injector.

 

Since those are the center 2 cylinders, I would suspect the head gasket is blown between them. Doing a compression check should show if I am right. Also remember it's got the infamous 0331 head that tends to crack in the same spot. Check for coolant in your oil right away.