My '02 tj 4.0 has been steadily running worse for a couple months now. Here is the problem...

after high-rev runs on the trail, shutting it off and then re-starting it will barely idle. sounds like it is loading up with fuel and backfires sometimes, then it eventually runs fine. Also, when getting in to the gas again immediately after an up-shift it will studder for a second then accelerate. Also sometimes when starting up in first gear and letting off the clutch it will hesitate and barely go.

motor has 53K miles (but a rough life at that)
It is a coil pack motor
I replaced all 4 Oxygen sensors, the TPS sensor, all the plugs, and cleaned the mass air flow sensor.
K&N air filter is clean, and I do not believe there are any vacuum leaks.
new fuel filter and nearly new fuel pump

anyone have a clue what could be wrong?

did you clean the IAC?

first i was thinking O2 sensors but you replaced them so then maybe CAT converter? prolly not but that's all i have right now:p

didnt check the IAC yet, Ill do that. I have 2 pre-cats at the exhaust manifold and I took the main cat off 2 years ago and it always ran fine until recently. thanks guys

fuel pump
fuel filter
injectors

just throwing shit out there:D

Maybe injectors as mentioned above. The only thing I could think of. Is it throwing any engine codes or anything???