If the car feels much slower after this you'll know it was mapped beforehand!!
Ps. A dealer always wants to do warranty work, they will look past most mods if they can get away with it.. Its where they make their money!
Car: 2010 Jaguar XFR (Cat-back exhaust)
Gone but not forgotten: Highly Modified E90 335i LCI M Sport Manual (circa 480BHP/500lb ft)