2000 Jeep Grand Cherokee 4.0 runs rough stalls, code P0301.

Question

Dad replaced all lifters because one was collapsed. Just put in a new block, etc. Misfire is bad and causes the Jeep to buck at highway speeds like it's coming apart. Today it stalled 3 times when slowing to a stop sign. It starts back up, but misfire returns around 40 mph.

Answer 1

P0301 is a misfire code, I would start by check the spark plugs #1 and ignition coil. You can also check the injector #1.