let me know how you get on, my egr valve has packed in twice.
the egr recirculates exhaust gasses from the bottom of the engine into the top when the car is idling. when your driving the valve should fully close.
Mine has jammed open twice, effectively choking the car with exhaust gasses. if it is the egr valve that's fooked the car will drive perfectly fine then when you stop at lights, or a roundabout in my case, as you try to pull off the car will cut out completely and then not restart.
if you need any more info on the egr, and
how to blank it off to stop it from ever causing a breakdown again giveus a pm or something.