Your idle air control valve could be stuck closed and not allowing air to bypass the throttle plate. Usually they can be removed and cleaned out with a spray can of brake or carb cleaner. Could be your throttle position switch also. Dirty air filter? Don't know if your year has an air filter box thermostat but if so it could be stuck and not closing the heated air intake. This will eventually cook the MAS unit. Did it start after a fillup? If so, could be bad gas. Good luck......