When not replaced or maintained properly vehicle could experience: no/hard start, long crank time, misfire, lack of power, inconsistent shifting, spark plug fouling, catalytic converter failure, poor fuel economy, check engine light. Import and/or domestic applications available. Designed and manufactured to operate reliably under all operating conditions and throughout the entire engine speed range for peak engine performance. Designed to meet or exceed OE specifications in form, fit and function. Coils produce the high voltage necessary to ignite the air/fuel mixture in the combustion chamber