PROBLEMS WITH STANG

when was the last time you changed the plugs, plug wires, fuel filter, and ran a bottle of injector cleaner through it? i would check the ignition stuff first, then go from there. and clean your mass air sensor.
 
Well everyone else has already mentioned the tune up stuff and all. So I'm gonna jump in and mention something I had problems with that might not be to common.

I switched to a 180* thermostat lately (stock is 192*) and my car started running to cold, like below the "N", and as a result it would sputter and backfire when accelerating. When I would push in the clutch the rpm's would drop real rapidly like it does when the engine is to cold. Is yours running to cool maybe? :shrug: My .02