Cold start it runs and drives fine. After it warms up,starts surging at normal speed. Within 3 to 5 miles after cold start up it will drop out of gear. Pressing gas pedal, engine revs but no response transmission. Let it coast til speed and engine rpms seem to feel like 2nd or 3rd gear. Pushing gas pedal at this point the truck is in gear and drives shifting gears until reaching around 55mph then drops out gear again. I have replaced shift selonoids, transmission speed sensor and transmission filter. Cleaned maf sensor. Obd2 says knock sensor 2circuit bank 2

Changed the throttle body, accelerator pedal, brake sensor control and tried to preform a " relearn" cycle. Won't kick out of limp mode.