Engine light and traction control light

Hi, my question is my traction control and engine light are almost always on. I have had it repaired numerous times I have had the throttle body replaced the throttle sensor the pedal sensor and some wires the each time it was repaired both lights came back on eventually anywhere from a few days to two months each time. I took it to AutoZone to have a diagnostic done and they would tell me the same thing as the mechanics the first mechanic got ticket to replace the throttle body throttle pedal and wires now each time he replaced these parts he told me that he could find nothing visibly wrong with these parts. He was unsure as what was wrong with the car so he asked one of his friends within GM his friend had him hook it up to a computer and had him go through the computer programming and was told that the main program was corrupted that either a factory reset or the module had to be completely replaced. The mechanic gave me my car back and said that he did not have the necessary equipment to perform this task and gave me the name another certified dealer in the area that could help me. So I take it to the certified dealer and as soon as I do though told me that it was the throttle sensor the needs to be replaced and that is why I was having all of these issues and yet when it was replaced after about three months the lights came back on. Please help.