If your vehicle is behaving erratically and you have problems with it running smoothly, it could be showing signs of ignition coil failure. The ignition coil transforms the battery's low voltage to the thousands of volts needed to create an electric spark in the spark plugs to ignite the fuel in order for your vehicle to run. The severity of the symptoms vary according to which of the ignition coils are failing. Some symptoms of failing ignition coils are; Backfiring, poor fuel economy, engine misfiring, stalling and general starting issues. Although ignition coils are supposed to last around 100,000 miles or more, we recommend having your coils inspected at every servicing interval.