Car stumbles

First thing in the morning when the car is cold,it runs fine.As it warms up, it wants to stutter,miss,etc. If I turn on the a/c it almost dies.Does it if i'm in drive or reverse.The car is stock and the opti,plugs,and wires are around 2yrs old.I'm not getting any codes,so I don't know where to check next.http://images.ibsrv.net/ibsrv/res/src:www.ls1tech.com/get/forums/images/smilies2/icon_confused.gifFigure if a sensor was bad ,I would get a code or something.Any ideas?Thanks

check the vacuum hose