this can be caused by a misfire or a fault in the TAC system(throttle actuator control) I would start with getting the truck scanned for trouble codes and a good throttle cleaning would help. This throttle body can get carbon build up and it throws off the base throttle setting. I use the GM cleaner(15$ at dealer) and a soft pipe brush. The dealers do a full service for 150$ that includes the injectors, air induction and throttle body cleaning. This is important maintenance for these trucks.
these are also known for intake manifold vacuum leaks and if the fuel pressure is low it will cause running issues and not set the check engine light.
let me know what you find with the codes and we go further