Replace Toyota 4 Runner Ignition Plugs Replacement. Explore Best Toyota 4 Runner Combustion Plugs & Toyota 4 Runner Ignition Plug. Maintaining the spark plugs in your Toyota 4Runner is crucial for optimal performance and fuel efficiency. To extend their lifespan, ensure regular checks for wear, a correct gap setting, and use of dielectric grease to prevent corrosion. If your 4Runner experiences rough idling, misfires, or difficulty starting, it's time to consider replacement. When selecting new spark plugs, opt for durable materials like iridium or platinum that offer longevity and improved conductivity. Installation is straightforward, but always adhere to the manufacturer's torque specifications to avoid damage. Shop our premium selection of spark plugs tailored for your 4Runner and enjoy a smooth, powerful ride with every turn of the key.