Service function guideSpark Plug and Coil Service

This comprehensive guide walks you through the complete spark plug and ignition coil service, from understanding the system's operation to verifying a permanent misfire repair. It is written for both experienced DIY mechanics and professional technicians who want a structured, methodical approach that works across a wide range of vehicles. You will learn how to diagnose misfire codes, prepare the engine safely, remove and inspect ignition components, and install new parts without damaging delicate threads or connectors. By the end, you will be able to perform the job confidently, confirm the repair with live data and test drives, and apply the correct aftercare to prevent repeat failures.