Would it be a vacuume leak or throttle body

I have a 94 saturn sc1 1.9l sohc 5spd
The problem I have is right from start up it idles around 2500 rpm
Only way it will idle down any is if you put in gear let off clutch
And hold break as if your starting to accel
And in gear if you let off clutch and gas its like you
Have cruise control on and will slowly accel
It just started a few days ago and my service eng light comes on but will
Go away after sitting for a few mins with eng off
Comes back on randomly and stays on till eng turns off again