HELP!!!!! idles funny and tries to die stumble loss of power etc

so i have an 03 tibby. 2..7l v6 6-speed. about 110k. while sitting in driveway idling it will all of a suddon try to die. drops rpm from 900 to about 200-300 then comes back up. also while driving and trying to accelerate it will cut out and try to die. acts like loosing spark or something. doesnt matter if it is cold, warm little throttle or lots of throttle. i know about a year ago i replaced the MAF sensor. it has dual exhaust stainless & intake. i know before it did have a CEL for something to do with being lean or having a intake leak. but light goes on and off. most of the time is off. there is no CEL on now. anyone have some idea's


please help!!!!