Genuine OEM Toyota Spark Plug, part number 9091901298. This spark plug is responsible for igniting the compressed air-fuel mixture within the engine's cylinders, initiating the combustion process that powers the vehicle. It is a critical component of the ignition system. This specific plug features an iridium tip, known for its durability and ability to provide a strong, consistent spark. Genuine OEM spark plugs ensure correct heat range, electrode gap, and material composition for optimal engine performance, fuel economy, and emissions control.