for me after I reset it the check engine light didn't come on, but I noticed the idle was still pretty bad, I just kept the rpms high enough from dropping and triggering the check engine light to come on, but yes after really really cleaning the EGR valve it works and sounds great, soo much better than before, I would spend a day scrubbing it out with a wire brush (I got 2 for 59c each at lowes, 1/2" they work great, get 2 or 3 b/c the bristles bend easily) and the shop size carb cleaner and just scrub and clean, I let the carb cleaner stuff sit in there over night just because I started it late one night and to get the carb stuff softer off the side.. basicly the end result was I could see the stock walls inside the EGR valve, so it was really clean, and everything is perfect now..
with that said, it is possible that with your symptoms that it's something else, like maybe a bad bpv or maybe a leak somewhere you don't know (the stock vac lines crack really easily, if you plan to do any mods to the car, getting all new vac lines are pretty cheap and are great for knowing the lines you have are not leaking and dried/cracked) but I would definitely clean the EGR valve and go from there