GMPartsGiant.com offers the wholesale prices for genuine 2014 Cadillac XTS parts. Parts like Fuel Supply System are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 3.6L. Model Code: 4 DOOR NOTCHBACK, LUXURY 4 DOOR NOTCHBACK, PLATINUM 4 DOOR NOTCHBACK, PREMIUM 4 DOOR NOTCHBACK.