First figure out what you have. You can not do anything until you do. First loook atthe engine near the starter and see if there is a crank shaft sensor beside the starter. If so the engine has been replaced with a 99, Check the part number on the ECM and report back to tell if it is a 99 or 01. If you have a 99 engine you must have a 99 ECM, harness and the crank sensor, If an 01 engine it will have a different ECM, harness and no crank sensor. Both engines have a Cam sensor but they are differnet.