Hi, been having some issues past few weeks with my car. It has 44k miles on it. 1.4L Turbo engine. Took it for a 3 hr trip a few weeks ago, went to pass a car on hwy, engine stumbled, followed by service traction control, service stabilitrack message. Message stayed on until vehicle turned off. I assumed it was a bad tank of gas. Put a bottle of HEET in tank, everything was fine after that for a few weeks. Again recently the engine seems to be misfiring under gentle accelerations in the city. I got it out on the hwy, tromped on the accelerator, and got both messages again. Messages stayed on until I shut her off. Took it to dealership last night where I bought it, still under GM certified used car 36k mile warranty, they call me and tell me throttle plate needs cleaning, also fuel injector system needs cleaned out. $85 diagnose fee, $90 throttle plate cleaning, $90 fuel system cleaning. I've always used BP 87 octane gas for this car. I think its all B.S. Gonna take car back, put some Seafoam fuel injector cleaner through it, and either replace or re-gap my spark plugs. I really can't see the throttle body being dirty on a 2 yr old car with only 44k miles. Their response to the service traction control and service stabilitrack messages were when there is a cylinder misfire, the car disables these functions, no codes on these. Cylinder misfire recommends throttle plate and fuel injector cleanout at 30k miles as per their maintenance schedule. In the back of my owners manual, this is not mentioned at all. WTF!!! Anyone else with experience have any comments? Greatly appreciated.