Denso 234-4138 Oxygen Sensor - Downstream Right, Upstream or Upstream Left

Denso OE Style Oxygen Sensor 234-4138

Denso 234-4138 is an OE-style heated oxygen sensor built for exact replacement and first-time fit. It is engineered for precise signal feedback in the exhaust stream, helping support proper air-fuel control, fuel economy, and emissions performance on select Toyota and Lexus applications.

Key Features

• Heated oxygen sensor with a specific-fit design
• OE Style construction for direct replacement on listed applications
• 4-wire configuration with male connector
• Threaded mounting with 0.708 in. thread diameter
• Wiring harness length: 8.27 in.
• Built with Denso’s aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination

Product Details

Denso 234-4138 is manufactured and tested to OE standards for vehicles that require a direct-fit oxygen sensor. This sensor is used in downstream right and upstream left positions on select Toyota 4Runner, FJ Cruiser, and Land Cruiser models, as well as Lexus SC430, GS430, LS430, LX470, and GX470 applications. If you are replacing a worn sensor on a Toyota 4Runner oxygen sensor or a Lexus upstream oxygen sensor, this OE-style part is built to match the original fit and electrical configuration.

This part cross-references Bosch 13441 and NTK 24560 for the same application.

What This Sensor Helps Address

• Check engine light concerns related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the engine control module
• Reduced fuel efficiency caused by aging sensor response
• Emissions test failures tied to a faulty upstream or downstream sensor
• Rough idle or drivability issues associated with inaccurate exhaust readings

Installation Notes and Fitment

Fits 2010-2012 Toyota 4Runner, downstream right. Fits 2010-2012 Toyota FJ Cruiser, downstream right. Fits 2002-2010 Lexus SC430, upstream left. Fits 2001-2007 Lexus GS430, upstream left. Fits 2001-2006 Lexus LS430, upstream left. Fits 2005 Lexus LX470, upstream. Fits 2005 Toyota Land Cruiser, upstream. Fits 2003-2004 Lexus GX470, upstream. Fits 2003-2004 Lexus LX470, upstream. Fits 2003-2004 Toyota 4Runner, upstream. Fits 2003-2004 Toyota Land Cruiser, upstream.

Verify connector style, thread size, and sensor position before installation. Use the listed vehicle position exactly as shown, since upstream and downstream sensors are not interchangeable on these applications.

Quality Assurance

Denso manufactures this OE-style oxygen sensor to strict original-equipment standards and tests each design for fit, function, and durability. The brand’s contamination-resistant trap layer is intended to help preserve sensor performance over time in demanding exhaust conditions.