Denso 234-4512 Oxygen Sensor - Downstream Rear or Downstream Right

Denso OE Style Oxygen Sensor for Toyota Sienna

Denso 234-4512 is an OE Style heated oxygen sensor built for exact replacement and first-time fit. It is engineered for the downstream right and downstream rear positions on select Toyota Sienna models, helping maintain accurate exhaust feedback for consistent engine performance and fuel economy.

The Denso OE Style line is built to match original equipment expectations, with precision construction and a specific-fit design for straightforward replacement on the correct application. This sensor also uses Denso’s aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination.

Key Features

• OE Style replacement oxygen sensor for direct-fit service
• Heated sensor design for faster operating response
• Specific fit with a threaded mounting type
• 4-wire configuration with female connector
• Wiring harness length: 19.69 in.
• Thread diameter: 0.708 in.
• Fits Toyota Sienna downstream right and downstream rear applications

Detailed Description

This Denso oxygen sensor, part number 234-4512, is designed for 2007-2010 Toyota Sienna downstream right applications and 2004-2006 Toyota Sienna downstream rear applications. It is a direct replacement sensor for vehicles that require a heated, specific-fit oxygen sensor with a threaded mount and 4-wire female connector. If you are searching for a Toyota Sienna oxygen sensor replacement, Denso 234-4512 provides the OE-style fit and configuration needed for the correct exhaust location.

Denso’s OE Style product line focuses on exact replacement parts that align with original equipment dimensions and electrical requirements. The built-in trap layer helps shield the sensing element from contamination, supporting stable sensor operation over time. This makes the Denso 234-4512 a practical choice for drivers and technicians servicing Toyota Sienna emissions control systems.

This part cross-references Bosch 15683 and NTK 24687 for the same application.

Common Issues This Sensor May Address

• Check engine light related to oxygen sensor performance
• Incorrect exhaust feedback from a worn downstream sensor
• Reduced fuel economy caused by inaccurate air-fuel monitoring
• Emissions test failure tied to sensor response issues
• Rough or inconsistent engine operation from faulty sensor data

Installation Notes and Tips

Confirm the sensor position before installation: this part is used in the downstream right or downstream rear location depending on model year. Verify connector style, wire count, and thread diameter against the original sensor before replacement. Because oxygen sensors are threaded into the exhaust stream, proper removal and installation practices are important to avoid damage to the sensor or exhaust bung.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for fit and function. The 234-4512 is built as a specific replacement for the listed Toyota Sienna applications, with construction intended to match original equipment requirements.