Ignition Coil Kit 2026: Autoexact Pack & Iridium Plugs

You can replace a single coil, but it's not recommended. Aging coils often fail at different rates, and a new coil may work harder alongside old ones, leading to uneven performance. Replacing all coils at once ensures balanced ignition and prevents future misfires.

Most iridium plugs come pre-gapped from the factory, but you should always check the gap with a tool. If adjustment is needed, use a specialized gap tool to avoid damaging the delicate iridium tip. Incorrect gapping can cause misfires or poor fuel economy.

Common symptoms include engine misfires, rough idling, reduced acceleration, a check engine light with codes like P0300-P0308, and decreased fuel economy. You may also notice the car struggling to start or stalling. Prompt replacement prevents catalytic converter damage.

Spark plugs typically last 60,000 to 100,000 miles with iridium types, while coils often last 80,000 to 120,000 miles. However, heat and vibration can shorten lifespan. Replace both as a set when one component fails to maintain consistent engine performance.

No, a standard replacement coil kit will not increase horsepower. Its purpose is to restore factory ignition performance. Aftermarket performance coils may claim gains, but without supporting modifications like a tune, they rarely produce measurable power increases for daily drivers.