Denso 3491 Spark Plug

Denso Iridium Long Life Spark Plug

Denso 3491 is an Iridium Long Life (SIP) spark plug built for OE-level ignition performance, durability, and emissions control. It is a direct replacement choice for select Toyota and Lexus engines, including Camry, Tacoma, Highlander, Avalon, Sienna, RX350, and ES350 applications.

The Denso Iridium Long Life line focuses on stable spark delivery and long service intervals using an iridium center electrode, platinum needle ground tip design, and OE-style construction. Part number 3491 is also referenced as Denso FK20HBR8 and Toyota 90919-01263 for the same application.

• Iridium center electrode tip for consistent ignition performance
• Platinum needle ground electrode tip design
• Needle-to-needle ground configuration for precise spark exposure
• 5000 ohm resistor for ignition noise suppression
• Copper center electrode core and nickel ground electrode core
• Flat seat, 14.00 mm thread diameter, 26.50 mm reach, 16.0 mm hex
• Pre-gapped at 0.8 mm

OE-Style Construction For Toyota And Lexus

This spark plug is manufactured to meet strict OE performance, durability, and emissions standards. It is a strong match for drivers servicing factory-equipped ignition systems in vehicles such as the 2020-2023 Toyota Camry, 2020-2023 Toyota Tacoma, 2019-2023 Lexus ES350, and 2020-2022 Lexus RX350. The Denso 3491 design supports reliable combustion characteristics in modern Toyota and Lexus engines that specify Iridium Long Life (SIP) plugs.

This part cross-references Denso Auto Parts FK20HBR8 and Toyota 90919-01263 for the same application.

Common Uses

• Restoring weak or inconsistent spark output
• Addressing rough idle caused by worn ignition plugs
• Correcting hard starting related to plug wear
• Reducing misfire conditions tied to aged spark plugs
• Maintaining OE ignition performance in Toyota and Lexus engines

Installation Notes

Verify engine application by year, make, model, and OE plug specification before installation. Confirm the 0.8 mm pre-gap and inspect coil boots, threads, and sealing surfaces during service. Use the correct torque procedure for the flat-seat design to avoid thread or sealing damage. This plug is compatible with select 2013-2023 Toyota and Lexus vehicles listed in the fitment data, including Camry, Tacoma, Highlander, Avalon, Sienna, RX450h, and GS350 applications.

Quality Assurance

Denso manufactures this spark plug to OE performance, durability, and emissions standards, supporting factory-level service expectations for Toyota and Lexus ignition systems.