I'm not sure if there is a link between the check engine light and too much oil in the crankcase. If anything, too much oil would cause some frothing to occur and your *oil pressure* light might come on, not the CEL. The check engine light usually relates to an emission control device, not a mechanical failure.
Joe is right - check the oil after the car has been sitting for more than 30 minutes.
2003 Midnight Blue SE AWD w/VDC
Colgan Bra, Mobil One, JWT POP charger
PAC aux input adapter, hardwired Escort Passport x50, KUDA mount for MP3 player, Porterfield R4S brake pads (now Akebono ProACT), ATE Superblue
Yokohama Envigor (much improved over stock Goodyears)
Lots of squeaks and rattles.