Denso 4701 Spark Plug

Denso Iridium TT Spark Plug 4701

Denso Iridium TT 4701 is a spark plug built for OE-style durability with a focus on power and torque. Its twin-tip design combines an iridium center electrode with a platinum ground tip to support consistent ignition performance across a wide range of import and domestic applications.

Compatible With vehicles such as the Toyota Prius, Honda Accord, and Mitsubishi Outlander Sport, this plug is a direct-fit option for many high-mileage and performance-oriented engines. The Denso 4701 is also cross-referenced as Denso Auto Parts IK16TT for the same application.

Key Features

• Iridium center electrode tip for precise spark delivery
• Platinum twin-tip ground electrode design for extended service life
• OE-style construction with performance-focused ignition output
• 5000 ohm resistor for electrical noise suppression
• Flat seat design with 14.0 mm thread diameter and 19.0 mm reach
• Pre-gapped at 1.0 mm for common applications
• Fits a broad range of vehicles including Toyota Prius, Honda Odyssey, and Jeep Compass

Product Details

The Iridium TT line is Denso’s twin-tip spark plug family, engineered to balance long-term durability with stable combustion performance. The 0.4 mm iridium center tip and 0.7 mm platinum twin-tip ground design help maintain a focused spark while supporting reliable starts, smooth idle quality, and efficient throttle response. Part number 4701 is used across many fitments from compact cars to SUVs, including applications for Toyota Yaris, Hyundai Elantra, and Mitsubishi Lancer.

Common Issues This Part Can Address

• Hard starting or extended crank time
• Rough idle and inconsistent combustion
• Misfire codes related to worn spark plugs
• Reduced throttle response from aged ignition components
• Service intervals overdue on OE-style ignition maintenance

Installation Notes and Tips

Verify engine code and plug specification before installation, especially on vehicles with dual-plug cylinder heads such as some Mercedes-Benz and Honda applications. Confirm the correct heat range, thread reach, seat type, and pre-gap against the vehicle service information. For best results, inspect ignition coils, boots, and plug wells before installing the new spark plugs.

Quality Assurance

Denso manufactures the Iridium TT 4701 as an OE-style spark plug designed to meet the demands of modern ignition systems while supporting long service life and stable performance.