Mitsubishi eclipse problem

My car is the 2002 eclipse gt spyder 3.0,  I've  
replaced the egr valve, all spark plugs and
wires, the distributor with camshaft sensor,
water pump timing, belts, pullys, all o2
sensors, and all catalytic converters, straight
pipes the last one but o2 sensor is still there,
nowstill has check engine light on.  Problem:
THE rpm jumps a little when cranking up.  
Why does my car do this????