1998 Nissan Maxima Rough idle

I'm a novice when it comes to car repair, but I seem to have a rough idle while the car is stopped in gear. I would have to change to neutral to keep the rpms steady. This happens in reverse also. But when I'm at highway speeds the car seems fine. I checked the codes and I have a small vacume leak evap and maf code. I noticed that the rubber seal between the MAF and filter is missing and dirt might have gotten in? Is the Mass Airflow sensor cleanable? I bought a MAF cleaner and am hesitant to use it? I also figure the evap code has something to do with the bypass valve and carbon canister. These seem to be common problems?