Walker 250-54029 Oxygen Sensor - Upstream

Walker OE Oxygen Sensor for Mazda 3

Walker Products OE Part Number 250-54029 is a heated, specific-fit oxygen sensor engineered for the upstream position on select 2004-2009 Mazda 3 California emissions ESV vehicles. It is built to deliver the diagnostic feedback the ECU expects, helping maintain proper engine management on the Mazda 3.

Key Features

• Heated oxygen sensor for upstream placement
• Specific-fit design for direct application matching
• 4-wire configuration with female connector
• Threaded mounting type with 18.0 mm thread diameter
• Wiring harness length: 15.67
• Overall length: 19.21
• Walker Products OE line for application-specific replacement

Detailed Description

Walker Products OE 250-54029 is an emission control sensor designed for vehicles that rely on accurate exhaust feedback to manage fuel delivery and emissions. This oxygen sensor is made for the upstream location on 2004-2009 Mazda 3 models with California emissions ESV configuration, where the ECU uses sensor input to monitor air-fuel conditions and adjust engine operation. The Walker Products OE line focuses on application-specific fitment and OE-style replacement for engine management systems, making this part a direct match for the listed Mazda 3 fitment.

This part number, 250-54029, is intended for drivers addressing a failed upstream oxygen sensor on a Mazda 3 and for repair work tied to emissions-related fault codes, poor fuel control, or MIL illumination. This part cross-references no listed alternate part numbers in the provided data.

What It Helps Address

• Check engine light related to upstream oxygen sensor faults
• Poor fuel economy caused by incorrect air-fuel feedback
• Rough engine operation from inaccurate exhaust readings
• Increased exhaust emissions from a failing sensor
• Stored ECU fault codes tied to the oxygen sensor circuit

Installation Notes and Tips

Fits 2004-2009 Mazda 3, upstream, California emissions ESV vehicles. Confirm the connector shape, 4-wire layout, threaded mounting, and sensor position before installation. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten sensor life and affect ECU feedback. Verify the vehicle’s emissions configuration before ordering to ensure the correct application.

Quality Assurance

Walker Products OE sensors are engineered as original-equipment replacement parts for specific vehicle applications. Walker Products has manufactured engine management and fuel system components since 1946 and operates as an Automotive ISO9001/TS 16949 certified company.