Q: I drive a 2010 chevy Malibu and wen driving my car jerks and rpms go up and down a little. Losing power

Although the check engine light is off, there may still be downloadable diagnostic trouble codes which might provide clues as to why the engine runs roughly. Possible causes of the trouble you are experiencing are uneven cylinder compression, fuel system problems (injectors, fuel pump, fuel filter, fuel pressure regulator, etc.), a vacuum leak, EGR leaks, an air induction fault like a stuck idle air control valve or a faulty throttle position sensor, problems with the mass air flow sensor, defective spark plugs, a weak coil and defective oxygen sensor(s). If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a rough idle diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.