I working on a 2003 chevrolet with a 5.3, cold air, cam, long tube headers, electric fans, thunder racing tune, put a fresh built trans in it, can't get the truck out of reduced power, keeps showing p1518,p1516 changed throttle body, wiring harness, checked wires all the way back to computer, checked grounds and still nothing it is about to drive me insane any suggestion would greatly be appreciated thanks

 

http://www.ls1truck.com/forums/mecha...e-power-3.html

 

I was getting the same prob...it was crimped wires/bend electrodes on the pig tail that got triggered when I hit a big bump. Make sure to position the wires such that they don't bounce around once its all together. R/

 

I'm having the same problem and its driving me crazy. I cant find any bent, broken wires. Where EXACTLY on the harness were you guys finding problems with the wiring?