Denso 234-5137 Air / Fuel Ratio Sensor - Upstream

Denso OE Style Air/Fuel Ratio Sensor

Denso 234-5137 is an OE Style heated air/fuel ratio sensor built for specific-fit BMW applications. It is precision-built and tested to OE standards for accurate replacement fitment on upstream locations.

For BMW 325Ci, 330Ci, X3, 325i, 330i, 525i, and 530i applications, this Denso air/fuel ratio sensor is made to match the original-style connection and sensor layout. The 38.66 wiring harness length, 5-wire design, male connector, and 0.711 thread diameter support direct replacement on the listed vehicles.

Key Features

• Part number: 234-5137
• OE Style line for direct replacement fitment
• Heated air/fuel ratio sensor for upstream use
• Specific fit for listed BMW applications
• 5-wire configuration with male connector
• Wiring harness length: 38.66
• Thread diameter: 0.711
• Built and tested to OE standards

Detailed Description

Denso 234-5137 is an emission control sensor for upstream air/fuel monitoring on select BMW models. The OE Style product line focuses on exact replacement dimensions and connector design, helping maintain the original sensor interface on 2003-2006 BMW 325Ci, 330Ci, X3, 325i, 330i, 525i, and 530i applications. This part cross-references Bosch 17215 for the same application.

Because air/fuel ratio sensors feed critical data to the engine management system, correct sensor type and fitment matter. This Denso sensor is a heated, specific-fit replacement intended for the listed BMW upstream positions, including 2003 BMW models from 3/03 and 2004-2006 applications.

What It Helps Address

• Check engine light related to upstream air/fuel sensor faults
• Rough idle caused by inaccurate exhaust mixture feedback
• Fuel trim issues from a slow or failing sensor signal
• Emissions test failures tied to sensor performance
• Poor drivability from incorrect air/fuel ratio readings

Installation Notes and Tips

Verify the vehicle year, model, and upstream position before ordering. This part is specific fit, so connector style, wire count, and thread size should match the original sensor on the vehicle. For best results, inspect the harness routing and connector condition during replacement on BMW 325Ci, 330Ci, X3, 325i, 330i, 525i, and 530i applications.

Quality Assurance

Denso manufactures and tests this sensor to OE standards for consistent replacement quality and first-time fit. The OE Style line is built around exact replacement dimensions and application-specific fitment for the listed BMW vehicles.