1998 4.0l 4x4 manual. 254,000 miles. recently experienced this while driving. the truck started to buck. its been getting worse for about a week.
Recent work done. New clutch kit, including master and slave cylinder. Full rebuild of transmission little less than 2 months ago.
Newer Maf sensor (already cleaned yesterday) Recent IAC (also cleaned) Newer throttle sensor, cleaned throttle plate. New pcv valve.
Newer O2 sensors.
A few weeks ago, I had the drivers side O2 sensor wire touch the manifold and stick to it, melting the connector on the sensor side not the engine side. My feeling was that this was the main cause. I got a new O2 sensor and installed it. The bucking is no better. Very bad under load, but a little noticeable at idle.