Common symptoms include engine misfires (P0300-P0312 codes), rough idle, loss of power, poor fuel economy, difficulty starting, and the check engine light illuminating. A failing coil may cause intermittent problems that worsen over time.

While not required, coils that are the same age may fail around the same time. Replacing all coils during a tune-up ensures consistent spark performance across all cylinders and prevents repeat repairs.

Yes. A weak or failing coil can cause incomplete combustion, which may damage spark plugs, catalytic converters, and even engine internals over time. Address ignition coil issues promptly to prevent collateral damage.