starts to run rough at 100klp then quits when slowed down

I have had 3 gm products since 2001 all 1500 models 2001 3.5 l 2013, 6.2, and now a 2015 3.5.

Each truck had the same problem, while driving at 100 klh they suddenly start to run rough, misfire, and loose power. If I slowed down to to let people pass or turn into my destination the truck would suddenly begin run normal. The next time this would happen happened randomly anytime, no pattern whatsoever.

Had dealer put on testing equipment nothing registered, no codes came up ever. Phoned Oshawa they have no idea what it could be. The cruise control would kick off just as motor started to run rough. Step on the gas no power seemed to suck for fuel.

Upon leaving work Monday 11/16/2015 I remote started my truck from the OnStar app. I did not get to the car in time before it shut off. I then attempted to restart the truck via the app and it came back Failed. I then tried with the remote itself and it would not work. I got into the truck and started it up only to receive a check engine light and stabilitrack light come on. The truck felt like it was struggling to run and was only running on 2 cylinders. I hit the OnStar button and they diagnosed the code and found that the engine was misfiring and the stable trak was having issues. The agent was very helpful and offered to have the truck towed to my house and to the dealer in the morning if i didn't feel comfortable driving home. She was able to advise the safest way to get the car home and the closest dealer to me for the morning. I took it to the dealer in the morning to have it fixed and after sitting in the waiting area from 745am to 11am they finally came out and said they needed to order another computer for the truck as one of them went bad. I was put in a rental and sent on my way. I called today 11/18 to check the status around 12pm and was told they were still waiting on the part. I called again at 430pm and was told GM had not delivered the part yet and will most likely not be ready until 11/19. Everyone has been very informative and a huge help but i just want my truck back! This is brand new with only 1,900 miles on it and should not be having these kind of issues.

Within 46 hours of purchasing this brand new truck it broke down. Pulled away from a stop light, made a left hand turn and heard a weird sound from the rear end. Traction light came on, check engine light came on and the truck was suddenly running on what felt like 2 cylinders. No acceleration power. Idling extremely rough. Pulled in to a parking lot and called the roadside service. Finally had a tow show up 2 hours later. Truck went back to the dealer for repair. They replaced the fuel injector and found that it didn't fix a thing. It's now been 8 days and not a word of what the solution is or when it'll be done. So glad I bought this little beauty!