theres lots of ways to do this but the first thing I'd do is isolate your egr to see if it's the problem. if your engine idles fine it's probably not leaking by on the exhaust side.. good.. so to see if it is a egr control problem disconnect the small hose going to the egr valve and plug it. the round metal part.. it may be comming from a vsv or the vacuum modulator. anyway plug it, drive and then see if it makes a difference.
