Also might try cleaning the throttle plate and intake with sensor safe carb cleaner and a (old) toothbrush. If this doesn't help, also could be the egr valve which can be removed relatively easily and cleaned out.

89 xcab 4x4 22re. 1.5" BJ spacers, 3" shackle and AAL + fender trim. 33x12.5 R15 MT/Rs, 15x10 rockcrawler streetlocks. 488 yukons by ZUK, detroit rear and true-trac front. 2 1/4" cat-back exhaust. Redline gear oil. Rear bumper by bentup.com.