MoparPartsGiant.com offers the wholesale prices for genuine 2003 Jeep Grand Cherokee parts. Parts like Throttle Body are shipped directly from authorized Mopar dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 4.0L, 8 Cyl 4.7L. Transmission: 4-Speed Automatic Transmission, 5-Speed Automatic Transmission.