sanitarium16

I'm coming up on 100,000 miles and my car was perfect. Idle was smooth and precise. All of a sudden I got on it a little and now my idle is rough. I have changed the plugs using stock motorcraft, wires using FRPP 9MM and the coil packs. I have also cleaned the MAF, temp sensor and idle air control motor which is about 6 months old. Oil was just changed using amsoil xl synthetic 5w30 and motorcraft fl820s. I have no idea why it is doing this now. The idle is not smooth it going up and down about 45RPMs and can be felt through the wheel. It doesnt do this in drive only in park! Also checked for loose hoses but they are all tight. PCV valve is good as well. Any ideas? Could it be mechanical? The car doesn't use any oil or blow any smoke.