Denso 234-4517 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor 234-4517

Denso 234-4517 is a heated, specific-fit oxygen sensor built for direct replacement in emission control applications. It is engineered for the 2001-2005 Lexus IS300 downstream position, with OE-style fitment for Cylinder 4, 5, and 6 applications.

The OE Style line focuses on exact replacement and first-time fit. Denso also uses an aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination, supporting stable engine operation and consistent fuel control.

Key Features

• Heated oxygen sensor for downstream exhaust monitoring
• Specific-fit design for direct replacement
• 4-wire configuration with male connector
• Threaded mounting type with 0.708 in. thread diameter
• 35.83 in. wiring harness length
• OE Style construction for the 2001-2005 Lexus IS300

Detailed Description

This Denso oxygen sensor, part number 234-4517, is designed for the downstream location on the 2001-2005 Lexus IS300. It is a heated sensor with a specific-fit layout, making it a direct replacement for the original emission control sensor in the listed application. The OE Style product line is built around exact replacement dimensions and connector configuration for straightforward service work.

As an oxygen sensor for the Lexus IS300, this unit helps the engine control system monitor exhaust oxygen content after the catalytic converter. Denso’s protective trap layer is designed to reduce contamination-related wear on the sensing element, which supports accurate signal output and long service life in demanding exhaust conditions. This part cross-references Toyota (e.g., 8946553120, 8946553190) for the same application.

What It Helps Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect air-fuel feedback from a worn exhaust sensor
• Reduced fuel economy caused by inaccurate sensor readings
• Rough engine operation tied to emission control sensor failure
• Inspection or emissions test issues on a Lexus IS300

Installation Notes and Tips

Verify the downstream location before installation and confirm the connector style, wire count, and threaded mounting dimensions match the original sensor. For the 2001-2005 Lexus IS300, this part is listed for the downstream position with notes for Cylinder 4, 5, and 6. Use proper exhaust sensor removal practices to avoid damaging the threads or wiring harness.

Quality Assurance

Denso manufactures and tests this OE Style oxygen sensor to strict original-equipment standards for replacement accuracy and consistent performance. The 234-4517 is built for direct-fit service on the Lexus IS300 and is backed by Denso’s OE-focused engineering approach.