So my car was sitting for awhile and turned it on today and just started up fine but i notice she was idiling weird and the driver side exhaust was kind of shaking as well and i had a weird matching burn after too..... could it be an 02 sensor i got that replaced like not even a year ago.... OR is it an exhaust leak because the driver side exhaust sounds funny... need help guys.. o ya the engine light back so i guess i gotta grab those codes