[2013ZL1FUN]

You really need to take this vehicle to a shop that has a person that knows how to use a diagnostic scanner and have this vehicle properly diagnosed. Anyone can do a parts cannon on any vehicle and maybe fix it. You are way beyond that point now. If you were in Ohio I could recommend a shop that has a scientific approach to car repair. That is really what is needed at this point because the semi routine maintenance stuff didn't work. Sorry to tell you those shops were just guessing.