all zx2 zetec motor parts will interchange. The items that will not interchange for all the years are items like the MAF sensor (98-99) and few other little things. The only real differences of the 2003 are the nice looking wheels, the 2003 only cloth seat pattern, the front facia, the healight support (under the bumper), the fog lights, the stereo and wiring (if you have the indash cd player, no longer trunk mounted changer), and the computer. The 2003 computer gave the car an increase of 5 ft/lbs of torque over the previous models, the horsepower rating stayed the same.
