Oil or coolant leaks can damage ignition coils—the leaks need to be repaired along with the ignition coil. Failing ignition coils can cause the engine to run roughly or a lack of power upon acceleration.The Check Engine Light will often flash when the engine is misfiring—continuing to drive under these conditions can damage the catalytic converter. A failed ignition coil can be the result of failures elsewhere in the ignition system. The ignition wires and spark plugs should be inspected and replaced if necessary.