ok here is the deal. i have an 02 2500 HO 6speed with an edge juice/attitude and air dog lift pump. when i get down on her real hard it seems to miss or stumble at 1500 to 2000 rpms. it does it briefly and then continues climbing. also at idle the tach jumps around at between 800 and 900. not enough to hear through the engine but you can see it in the tach. any ideas on what could be the cause or is this normal?