I bought this truck off a used car lot, has aftermarket parts on it, 4" turbo back, cold air not sure at this time if it has a program on it, auto trans and pretty sure it has a built trans with shift kit. Anyways back to my problem. It doesnt do it all the time but more noticable during driving it pretty hard or pulling trailer. at highway speeds cant tell a difference normally but at idle it will all of a sudden run rough an the truck will jump if stopped at light if im not paying attention an not much pressure on brake pedal, if i give it throttle it smokes black and runs light a raped ape with tons of power, then will stop and run normal, sometimes month or so between or every day. if i turn truck off then back on it will go back to normalfor a bit. injector stucking open possible? wiring bad somewhere? also no check engine light ever an no logged codes, i have no idea where to even start!!!!!