I scanned with my aeroforce today and was surprised (because my SES light isnt on) to see a p0403 and p0405 which are also EGR related. When I went to inspect it I saw that it wasnt there..lol. Apparently the previous owner deleted it. So first thing I'd check is if you still have one. If you do and you need to replace it, there are a bunch of people here that have deleted theirs and have it lying around and will sell it for a lot cheaper than brand new.