Walker 350-34157 Oxygen Sensor - Downstream

Walker 350-34157 Oxygen Sensor for Mini

Walker Products 350-34157 is a heated oxygen sensor built as a specific-fit OE replacement for downstream applications. It is engineered for vehicles that need accurate ECU feedback to help maintain proper fuel control and emissions performance.

Key Features

• Heated oxygen sensor design for downstream monitoring
• Specific-fit application for the listed Mini models
• 4-wire configuration with male connector
• Threaded mounting type with 18.0 mm thread diameter
• Wiring harness length: 23.15 in.; overall length: 26.69 in.
• Walker Products Aftermarket line for engine management and oxygen/air-fuel sensor replacement

Product Details

The Walker Products Aftermarket line focuses on engine management sensors built for OE-style replacement needs. Part number 350-34157 is designed for downstream use on select Mini Cooper, Mini Cooper Countryman, and Mini Cooper Paceman models, including applications that call for bank 1 sensor 2 feedback. As an oxygen sensor, it helps the ECU monitor exhaust conditions so the vehicle can maintain the correct air-fuel strategy and detect sensor-related faults.

Fits 2006 Mini Cooper, downstream. Fits 2007-2015 Mini Cooper, downstream. Fits 2011-2016 Mini Cooper Countryman, downstream. Fits 2013-2016 Mini Cooper Paceman, downstream. Fits 2017 Mini Cooper Countryman, downstream. This part number, 350-34157, is built for specific vehicle fitment rather than universal use.

What It Helps Address

• Check engine light related to downstream oxygen sensor faults
• Poor engine performance caused by incorrect exhaust feedback
• Increased fuel consumption from inaccurate sensor readings
• Higher exhaust emissions from a failing oxygen sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes

Verify the connector shape, wire count, and threaded mounting location before installation. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten service life. Confirm the vehicle uses the downstream bank 1 sensor 2 position listed for the application before replacing the sensor.

Quality Assurance

Walker Products states that its engine management sensors are developed as OE replacement parts and manufactured under Automotive ISO9001/TS 16949 quality systems. Since 1946, the brand has supplied engine management and fuel system components for vehicle service applications.