Denso 234-4504 Oxygen Sensor - Downstream

Denso 234-4504 Oxygen Sensor for Toyota Highlander

The Denso 234-4504 is a heated, OE-style oxygen sensor built for specific fitment on the 2004-2007 Toyota Highlander, downstream position. It is engineered for direct replacement performance with the correct connector, thread size, and harness length for a first-time fit.

For drivers searching for a downstream oxygen sensor for 2004-2007 Toyota Highlander models, this Denso sensor is built to match OE requirements and restore accurate exhaust feedback. The OE Style line focuses on exact replacement fitment and consistent sensor response.

Key Features

• Specific-fit oxygen sensor for the downstream location
• Heated sensor design for faster operating response
• 4-wire configuration with female connector
• 31.50-inch wiring harness length
• Threaded mounting with 0.708-inch thread diameter
• OE Style replacement from Denso

OE Style Replacement Details

Denso’s OE Style line is built around exact replacement dimensions and application-specific fitment. The 234-4504 follows the original equipment approach for the Toyota Highlander, helping ensure the sensor installs in the correct downstream location without modification. Denso also uses an aluminum oxide trap layer to help protect the sensing element from silicone and lead contamination, supporting stable engine management and long service life.

This part cross-references Toyota 8946548120 and 8946548190 for the same application. It also cross-references Bosch 15986 for related OE-style replacement needs.

Common Issues This Sensor Can Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect exhaust oxygen readings reported to the engine control system
• Reduced fuel economy caused by a worn sensor
• Slow sensor response from age or contamination
• Emissions test failures tied to oxygen sensor performance

Installation Notes and Tips

Verify the downstream location before installation and confirm the connector style matches the vehicle harness. The threaded mounting design and specific-fit layout are intended for direct replacement on 2004-2007 Toyota Highlander applications. Inspect the exhaust bung threads and wiring routing before tightening the sensor into place.

Fits 2004-2007 Toyota Highlander, downstream. Search terms such as 2004 Toyota Highlander downstream oxygen sensor, 2005-2007 Toyota Highlander O2 sensor, and Denso 234-4504 Toyota Highlander replacement all point to this application.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for fit and performance. The OE Style design reflects Denso’s focus on exact replacement dimensions, correct application matching, and durable sensor construction for dependable operation.