Please help! I have a 2014 denali 6.2L DTC p2127 p2138 Driving along and for no apparent reason my service trac control, service stabilitrak, and reduced engine power come on. It shows the 2 DTCs above. I changed the pedal pos sensor, didnt fix it so I thought maybe got a bad part and changed it again with oem parts. Still didn't fix it, next I changed the throttle body and throttle pos sensor, that didnt fix it. I've traced wires and checked plugs, nothing appears wrong. If I clear the code it will run like nothing happened for anywhere from 5 minutes to 2 months. I've had it at 2 different dealers and neither can find or fix the problem. I'm at the end of my abilities I think. Any advice is greatly appreciated.