My car idles rough when its at a stop or in Park. Other than that it drives fine. Happened immediately after cleaning the EGR valve. Any idea what may be causing this?

 

Which approach did you go with for cleaning it? Did you remove UIM, IACV? More info needed...................

 

I didnt touch the UIM or IACV. I took out the EGR valve itself and cleaned the non-electric parts (99 Maxima) with some throttle body cleaner. Got a lot of gunk out and then went on to clean the pipes with the same cleaner and a coat hanger.

Now here's the thing. When I was cleaning the EGR valve, I took out the 3 torx screws and the round piece that looks like it has fan blades fell out and I dont know if I put it in right side up or upside down. I believe that my EGR valve might be stuck open and as a result I'm getting a rough idle ( too much exhaust gases in combustion chamber).

Does any of this make sense?
Help plz.