06-23-2016, 07:37 AM
Left field answer. Have you checked the timing or taken the valve cover off to look at the belt and cam gears? It is possible that the timing belt was put on incorrectly and is causing your idle issue which would explain why your car "feels" faster, and is running lean. If whoever did the replacement caused the issue and couldn't figure out how to fix it, that could explain how the car ended up at a shady car dealership for so cheap after having it replaced.