Hello, Ive recently bought a Geo Tracker with the 1.6 4 cylinder 5 speed, and I'm having some issues with it. It idles very low, hesitates when you hit the gas, revs up very slowly and has trouble revving past 2300 rpm. Currently not drivable. Ive replaced the Mass Air Flow sensor, all new exhaust from the down pipe back, new fuel filter, new cap, rotor, and wires. I hate to keep throwing parts at it if they wont fix the problem. Any help????? Thank you!