I went through every one of the routine maintenences for my car and found the only thing i haven't replaced or cleaned was the EVAP. It has the check valve and the canister. The manual says it could cause rough idle so how do i check it or replace the necessary parts? The stupid manual will not go into any detail like where it is located or what should be cleaned or needs to be replaced. Is this something i should just buy a new one of or is it very rare it will cause problems?

 

The EVAP canister is located by the fuel tank. I don't think that is the source of your problem though. Have you tried cleaning the IAC motor?