I recently bought a 2005 grand caravan up here in ontario. The cel light was on and was diagnosed at the used car lot I got it from( they had an actual diamler chrysler scanner) as p0405. The egr was then replaced with a genuine mopar egr. The comp was reset and 100 feet down the road the cel lit back up. It was hooked back up to the scanner and read as p0405. EGR low again!
The single metal tube running to the top of the engine from the egr was clear and breathing easy. Where else should I look? What else is there to do. On the same note, it does run jerky just above idle, like a bad driver using a stick-shift for the first time but runs fine on the highway. I hope someone can help me.

Thanks!