Like some of the guys have suggested, I'd do a full tune up on the car. Fresh set up plugs, oil change, transmission service, higher octane fuel, etc. Then I'd consider a CAI and tune, and possibly upgraded coils.
2014 Mustang GT 6-Speed Manual
Major Mods: ProCharger P-1SC-1 Stage II, MGW Race Spec Shifter, Eibach Sportline Springs