Hi, I got a little problem (I hope) with my car.. The CEL light was coming on since I got the car but now the car is acting kinda wierd.. When im stoped at a stop light my RPM's iddle at 400-600 they go up and down (not always tho), and when I accelerate hard my car seems to be a little weak at high RPM's.. When the RPM's reach 4000-5000 RPM's I get more power for like 1 sec then it goes back to weaker power

, The CEL light also comes on and off, usualy goes off when im downshifting, or pressing in the clutch, anyone got any idea's? Help PLZ
ALSO THERE IS A LITTLE BIT MORE THEN NORMAL OIL IN MY CAR.. COULD THAT BE THE PROBLEM..?? ITS OVER FULL BY LIKE 1/4 OF AN INCH..
Thnx..