Denso 234-5743 Air / Fuel Ratio Sensor - Upstream

Denso OE-Style Air/Fuel Ratio Sensor

Denso 234-5743 is a specific-fit, wide-band air/fuel ratio sensor built to OE-style standards for accurate replacement on supported BMW applications. It uses a 5-wire design with a male connector and a 15.24 harness length for direct-fit service on upstream locations.

Compatible With 2012-2018 BMW 320i, Upstream, and other listed BMW 2.0L turbo applications, this sensor is built for exact replacement and first-time fit. The Denso Air / Fuel Ratio Sensor - OE Style line focuses on OE-level construction and precise calibration for dependable signal output.

Key Features

• Wide-band air/fuel ratio sensor for upstream exhaust monitoring
• Specific fit design for listed BMW applications
• 5-wire configuration with male connector
• 15.24 harness length for direct replacement routing
• Standard replacement grade for OE-style service
• Denso 234-5743 for BMW 320i, 328i, X3, X5, and related models

Detailed Description

Denso 234-5743 is engineered as an OE-style air/fuel ratio sensor for BMW vehicles that require upstream wide-band sensing. Denso manufactures and tests these sensors to strict OE standards, with precision-built components intended to match the original sensor’s fit and function. That makes this part a practical choice for BMW 320i, BMW 328i, BMW X3, BMW X5, and other supported models where accurate air-fuel feedback is critical to engine management.

This part cross-references Bosch 17272 and Gates 24364 for the same application. The Denso 234-5743 part number is also commonly referenced in interchange listings for replacement lookup and catalog matching.

What It Helps Address

• Check engine light related to upstream air/fuel ratio sensor faults
• Rough idle caused by incorrect mixture feedback
• Reduced fuel control accuracy from a failing wide-band sensor
• Driveability issues tied to slow or inaccurate sensor response
• Emissions test failures caused by sensor performance problems

Installation Notes and Tips

Install this sensor in the upstream position only where listed. Verify connector style, wire count, and harness length before installation, and compare the old sensor to the new Denso 234-5743 unit for routing and plug match. On BMW 320i and BMW 328i applications, confirm the exact engine and model year against the fitment list before service.

• Fits 2012-2018 BMW 320i, Upstream
• Fits 2013-2018 BMW 320i xDrive, Upstream
• Fits 2015-2018 BMW X4, Upstream
• Fits 2016-2018 BMW X5, Upstream
• Fits 2013-2017 BMW X3, Upstream
• Fits 2014-2016 BMW 228i, Upstream
• Fits 2015-2016 BMW 228i xDrive, Upstream
• Fits 2012-2016 BMW 328i, Upstream
• Fits 2014-2016 BMW 328i GT xDrive, Upstream
• Fits 2013-2016 BMW 328i xDrive, Upstream
• Fits 2014-2016 BMW 428i, Upstream
• Fits 2015-2016 BMW 428i Gran Coupe, Upstream
• Fits 2014-2016 BMW 428i xDrive, Upstream
• Fits 2015-2016 BMW 428i xDrive Gran Coupe, Upstream
• Fits 2012-2016 BMW 528i, Upstream
• Fits 2012-2016 BMW 528i xDrive, Upstream
• Fits 2012-2016 BMW Z4, Upstream
• Fits 2012-2015 BMW X1, Upstream

Quality Assurance

Denso builds this Air / Fuel Ratio Sensor - OE Style line to strict OE standards and tests each component for replacement accuracy and fit consistency. The result is a direct-fit sensor intended to match the original equipment application on supported BMW models.