Jeep Bucks

Wasn't sure if this belongs in Modified or OEM section. So whenever I drive me Jeep for extended periods of time (say 40mins or more) on the highway I will get this buck/jerk. The entire Jeep will buck/jerk and then be fine. The gauges all look normal, no dtcs, trans fluid gets a drain and fill with ATF 4 and Lucas about ever 20k-25k miles. This has been going on for a while and it didn't really bother me till I moved and my commute to work is an hour on the highway.

Here is some info about the Jeep:
2000 XJ
4.0L (300,100 miles on it) , AW4 (aux trans cooler), NP231 w/ PORC SYE
4.5inch lift
32" tires
LP30, 8.25 both with 3.55s

Any help would be greatly appreciated thanks.

Bucking, stalling, and backfiring are most often an O2 sensor issue. If your O2 sensors and sensor wires test good, one might suspect thermal failure of an engine sensor. The Crankshaft Position Sensor would be the most common sensor to suffer from heat exhaustion.