Why do I have a rough acceleration and vibration in gas pedal at idle?

There are a number of potential causes: Improper Fuel Pressure Insufficient Fuel Quality Malfunctioning Heated Oxygen Sensor (HO2S) Leaking Intake Manifold Gasket(s) Malfunctioning Mass Air Flow (MAF) Sensor Leaking Throttle Body Boot Leaking Engine Vacuum Fuel Injectors Fuel Pressure Intake Plenum Boot Exhaust Camshaft Actuator Catalytic Converter(s) Engine Valve Timing Timing Chain Do you have any codes stored in your computer system? We offer a free vehicle courtesy check that can help you pinpoint the cause. Jeff Basch AAMCO 972-429-8504

WHY was the alternator changed , and is the check engine light on?