Jeremy L Ralston

hello, i am need of serious help. my brothers 2011 silverado 4x4 5.3 ecu went bad so i replaced it, programmed it etc. when i attempted to start it the dash said " engine power reduced, service traction control and service stabilitrac. i have read so many posts on this subject to no avail. since then my brother and i have replaced the ecu, tps and everything else we have read that could cause these problems. my question is how can three new different ecu's and three new tps's all have the same problem? is there a way to clear the ipc of these codes? if im in the wrong place for posting this i truly apologize. this is all new to me. the truck starts but will not throttle up at all and idles really rough. again i apologize if im in the wrong place for posting.