I have a 2002 sport LS. I have swapped the og v8 for a 2004 3.9 v8. I had to swap the whole wiring harness from front to back. Also every thing in between. All modules ecm, front, back modules. ALL OF IT, heater core-blower fan assembly. OK - NEW PLUGS,COILPACKS,ETC SENSOR, TRACKED ALL...