Denso 4501 Spark Plug

Denso Platinum TT Spark Plug 4501

Denso Platinum TT 4501 is a secondary ignition spark plug built for direct-fit service across a wide range of import and domestic applications. Its twin-tip electrode design is engineered to promote faster flame travel for more complete combustion, helping restore consistent ignition performance in vehicles such as the Honda Accord, Toyota Corolla, and BMW 325i.

Key Features

• Twin-Tip ground electrode design for quicker flame propagation
• Platinum center electrode tip for durable ignition performance
• Copper center electrode core for efficient heat transfer
• Nickel ground electrode core material
• 5000 ohm resistance for suppression of electrical noise
• Flat seat design with 14.00 mm thread diameter and 19.00 mm reach
• Pre-gapped to 1.0 for straightforward installation
• Manufacturer heat range 16

Platinum TT Line Details

Denso’s Platinum TT line combines a platinum-tipped center electrode with a titanium-enhanced twin-tip ground electrode. The design focuses on stable spark delivery and efficient combustion, making it a practical OE-style replacement for vehicles that call for a 14 mm, flat-seat spark plug. Part number 4501 is also referenced in applications that use Denso PW16TT.

Detailed Description

This Denso spark plug is built for engines that need reliable secondary ignition performance and consistent combustion across a broad operating range. The twin-tip configuration helps the spark kernel develop quickly, while the platinum tip supports longer service life than conventional copper-only designs. With a 20.6 mm hex size and 19.00 mm reach, Denso 4501 is suited to many older and late-model applications listed in the fitment data, including Hyundai Sonata, Kia Optima, and Land Rover Range Rover coverage.

Compatible fitment includes 1990-2005 Hyundai Sonata, 2001-2006 Kia Optima, 1987-2002 Land Rover Range Rover, 1984-2000 Dodge Caravan, and 1969-1988 Toyota Corolla applications shown in the catalog data.

What It Helps Address

• Rough idle caused by worn spark plugs
• Hard starting from weak ignition output
• Misfire conditions tied to degraded plug electrodes
• Reduced combustion efficiency from inconsistent spark delivery
• Ignition noise suppression needs in electronic systems

Installation Notes and Tips

Verify thread diameter, reach, seat type, and heat range against the vehicle specification before installation. The pre-gap size is listed at 1.0, so confirm the engine’s required gap and adjust only if the application calls for it. Use proper torque procedures for flat-seat plugs and inspect ignition wires or coils if the old plugs show signs of fouling or uneven wear. This part fits many vehicles across the 1959-2006 model years, so confirm the exact engine application before ordering.

Quality Assurance

Denso manufactures this Platinum TT spark plug to OE-style dimensional and performance standards for secondary ignition service. The platinum-tipped, twin-tip design is intended to support consistent spark quality and combustion stability in the listed applications.