Each 2013 Ford Focus ignition coil transforms low battery voltage into thousands of volts to activate the spark plugs and start combustion. Rough idling, reduced MPG, and weakened acceleration are common signs of worn-out coils, and problems with these parts can cause a Check Engine Light or starting trouble too. Shop online today for new 2013 Focus ignition coils and get Free Next Day Delivery or pick up your parts at a store near you.