Denso 3426 Spark Plug

Denso Iridium Long Life Spark Plug 3426

Denso 3426 is an Iridium Long Life spark plug built for OE-level ignition performance, durability, and emissions control. It uses an iridium center electrode with a platinum needle ground design to support stable spark delivery in a wide range of Toyota, Lexus, Subaru, Honda, Acura, and Volvo applications.

The Iridium Long Life (SIP) line focuses on extended service life and consistent ignition characteristics for vehicles that call for a fine-wire plug. This part number is a direct service option for many late-model engines, including Toyota Camry, Lexus ES350, and Subaru Legacy applications.

Key Features

• Iridium center electrode for precise spark and long service life
• Platinum needle ground electrode tip design
• Needle-to-needle ground configuration for controlled ignition performance
• 5000 ohm resistance for OE-style electrical suppression
• 1.1 mm pre-gap size
• 14.00 mm thread diameter, 26.50 mm reach, and flat seat design
• Compatible with a broad range of OE replacement applications

Detailed Product Overview

Denso 3426 is engineered to meet strict OE performance, durability, and emissions standards. The copper core center electrode supports heat transfer, while the iridium tip helps maintain consistent firing characteristics over extended service intervals. The nickel ground electrode core and platinum needle tip design are selected to support reliable ignition under everyday driving conditions.

This spark plug cross-references DENSO Auto Parts FK20HR11 for the same application. It is also used in select Honda, Subaru, Toyota, and Volvo OE part number applications, making it a practical replacement choice for service work on vehicles such as Toyota Camry, Toyota Avalon, and Lexus RX350.

Common Issues This Spark Plug Can Address

• Rough idle caused by worn spark plug electrodes
• Hard starting from weakened ignition output
• Misfire codes related to degraded spark delivery
• Reduced fuel economy from inconsistent combustion
• Loss of throttle response from aged ignition components

Installation Notes and Tips

Verify engine-specific fitment before installation, especially on applications that use different plug counts or special service procedures. Confirm the specified gap and torque settings for the vehicle, and inspect ignition coils, boots, and seals during service to avoid repeat misfire concerns. This part is listed across multiple model years, including 2007-2017 Toyota Camry, 2007-2016 Lexus ES350, and 2015-2019 Subaru Legacy applications.

Quality Assurance

Denso manufactures this spark plug to OE performance, durability, and emissions standards. The Iridium Long Life (SIP) construction is intended to deliver consistent ignition quality in service applications that call for a long-life iridium plug.