Fuel pump, fuel filter, cam timing. It's possible that the timing belt jumped teeth on the cam gears...that would cause the motor to run rough and sound like it was misfiring, and be sluggish.
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2015 Ford Mustang GT Fastback - Ingot Silver - 6M - Performance Package - Gibson Catback, JLT CAI, FR 47lb injectors, BAMA E85 tune, Eibach Sportline, BMR wheel hop kit, UPR oil separator, Steeda shifter bushing/bracket
Team B.O.B.® - Ballaz on a Budget