Q: Car stumbles at idle but fine when drive or push gas peddle

Hello, thank you for writing in. There are a huge number of components that can contribute to a rough idle. Always start by scanning the vehicle for diagnostic codes regardless of a warning light being on. If no codes come up that help direct you, we have to start testing the fuel, air, and spark systems. Start by checking the condition of your spark plugs, and making sure they are in good condition. Secondly, you will want to make sure your throttle body and air intake sensors are all clean, dry, and tight. You may also want to visually inspect the idle air control valve for obvious signs of damage or excess contamination. The fuel pressure, battery, and alternator may also need to be tested. For more help with diagnostics, contact our service department to schedule an appointment.