Posted on 5/29/2026
A weak spark does not always make a big scene right away. It may show up as a rough start, a quick stumble when you press the gas, or a check engine light that flashes once and then settles down. That is what makes ignition problems annoying. Spark plugs and ignition coils work together every time the engine fires. When one starts to wear or fail, the symptoms can feel small at first, then turn into misfires, poor fuel economy, and catalytic converter damage if the problem is ignored. 1. What Do Spark Plugs Do? Spark plugs ignite the air-fuel mixture in each cylinder. That spark has to happen at the right moment, with enough strength to create clean combustion. As plugs wear, the gap can widen, and the spark can weaken. The engine may still run, but it may start harder, idle rougher, hesitate under load, or use more fuel than normal. 2. What Do Ignition Coils Do? Ignition coils create the high voltage needed for the spark plugs to fire. Many mod ... read more