I just did my egr but my problem was the bolts loosening, so I didnt pay much attention to detailed cleaning of it. As for your idle issue, I am not sure it the computer monitors and adjusts the idle over time or not, but since you cleaned it all out maybe the senors are working better changing the info sent to the computer. Anyway my suggestion if you havent already done it is disconnecting the battery for a few minutes (cant remember the required time) to clear any ecm setings. Hope that helps.