Denso 3335 Spark Plug

Denso Iridium Long Life Spark Plug for Subaru

The Denso 3335 spark plug is an Iridium Long Life ignition component built for OE-level performance, durability, and emissions control. It is a direct-fit choice for Subaru Legacy and Subaru Outback applications from 2010-2012, with the precise electrode design and heat range needed for consistent combustion.

For drivers searching for a Subaru Legacy spark plug or Subaru Outback spark plug replacement, this Denso 3335 part number matches the factory-style application and supports stable ignition performance over extended service intervals.

Key Features

• Iridium center electrode tip for fine-wire ignition performance
• Double Platinum Chip ground electrode tip design
• 5000 ohm resistor for ignition noise suppression
• 1.1 mm pre-gap size for OE-style setup
• 14.00 mm thread diameter with flat seat design
• 19.00 mm reach and 16.0 mm hex size
• Nickel ground electrode core and copper center electrode core
• Manufacturer heat range 20

Product Details

Denso 3335 is part of the Spark Plug - Iridium Long Life line, a product family focused on long-service ignition performance with OE fit and function. The iridium center electrode helps maintain a precise spark point, while the platinum ground electrode design supports durability under repeated heat cycles. Built to meet strict original-equipment performance, durability, and emissions standards, this spark plug is a practical replacement for 2010-2012 Subaru Legacy and 2010-2012 Subaru Outback models.

This part cross-references DENSO Auto Parts SK20R-P11 for the same application.

What It Helps Address

• Rough idle caused by worn spark plugs
• Hard starting from weakened ignition output
• Misfire conditions related to plug wear
• Reduced fuel economy from inconsistent combustion
• Loss of throttle response from degraded spark quality

Installation Notes and Tips

Verify the 14.00 mm thread diameter, 19.00 mm reach, flat seat, and 1.1 mm pre-gap before installation. Use the correct torque specification for the Subaru Legacy or Subaru Outback engine, and inspect ignition coils and plug wells for wear or contamination while servicing the plugs. Confirm vehicle year and engine application against the listed fitment before ordering.

Quality Assurance

Denso manufactures this spark plug to original-equipment performance, durability, and emissions standards, making it a direct replacement option for Subaru ignition service. Confirmed fitment includes 2010-2012 Subaru Legacy and 2010-2012 Subaru Outback.