Denso 234-5071 Air / Fuel Ratio Sensor - Upstream

Denso OE Style Air/Fuel Ratio Sensor

The Denso 234-5071 air/fuel ratio sensor is a specific-fit, heated emission control sensor built for precise replacement on select applications. It is engineered to match OE-style requirements for accurate signal response and a first-time fit on the vehicle.

Compatible with 2008-2015 Smart Fortwo, upstream, this sensor supports proper air-fuel monitoring for the engine management system. The OE Style line focuses on direct replacement fitment and consistent connector and harness configuration for service work that follows factory specifications.

Key Features

• Part number 234-5071 air/fuel ratio sensor
• Heated sensor design for faster operating readiness
• Specific fit application for direct replacement use
• 5-wire configuration with male connector
• Wiring harness length: 13.15
• Thread diameter: 0.711
• OE Style product line for factory-style fit and function

Detailed Description

Denso manufactures this air/fuel ratio sensor to OE standards for accurate replacement on the upstream position. The sensor is built with the correct connector style, wire count, and harness length to match the original installation on 2008-2015 Smart Fortwo models. If you are replacing a worn or failed upstream sensor, the Denso 234-5071 provides the correct configuration for service on the Smart Fortwo platform.

This part cross-references Bosch 17444 for the same application. It also cross-references Mercedes-Benz 0055429818 for the same application.

What This Sensor Helps Address

• Check engine light related to air/fuel ratio sensor faults
• Rough idle caused by incorrect upstream sensor readings
• Fuel trim issues from inaccurate exhaust oxygen feedback
• Reduced drivability from delayed sensor response
• Service replacement for a failed OE-style upstream sensor

Installation Notes and Tips

Verify the connector, wire count, thread diameter, and upstream location before installation. Confirm the vehicle is a 2008-2015 Smart Fortwo and compare the original sensor routing to the 13.15 harness length for proper fitment. Use the correct service procedure for the exhaust sensor location and inspect the connector terminals and wiring path before final assembly.

Quality Assurance

Denso states that this OE Style sensor is manufactured and tested to strict original-equipment standards. Each component is precision-built for exact replacement fitment, supporting consistent installation on the specified Smart Fortwo applications.