Walker 250-21034 Oxygen Sensor - Upstream

Walker OE Oxygen Sensor for Mazda

Walker Products OE oxygen sensor Part Number 250-21034 is a specific-fit replacement built for upstream exhaust monitoring on select Mazda applications. It is engineered to deliver the ECU feedback needed for proper fuel control and emissions management on 1990-1992 Mazda MX-6 and 1990-1991 Mazda 626 turbo models.

Key Features

• Specific-fit oxygen sensor for targeted vehicle applications
• Non-heated sensor design
• Threaded mounting type with 18.0 mm thread diameter
• Radiused polygon male connector
• 15.28 in. wiring harness length
• 20-gauge wire construction
• Overall length: 18.82 in.

Product Details

Walker Products OE line focuses on original-equipment-style replacement sensors for engine management systems. Part Number 250-21034 is built for upstream placement, including Bank 1 Sensor 1 applications on Mazda MX-6 and Mazda 626 turbo models. As an oxygen sensor, it monitors exhaust oxygen content so the ECU can adjust air-fuel delivery and maintain proper drivability and emissions performance.

This part cross-references no listed aftermarket part numbers in the provided data. For buyers searching Mazda MX-6 upstream oxygen sensor or Mazda 626 turbo Bank 1 Sensor 1 replacement, 250-21034 is the direct OE-style option to review.

What It Helps Address

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

Installation Notes and Tips

Verify the connector shape, thread diameter, and upstream position before installation. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten service life and affect signal quality. Confirm the vehicle application against the fitment list for 1990-1992 Mazda MX-6 and 1990-1991 Mazda 626 turbo models before ordering.

Quality Assurance

Walker Products OE sensors are developed as replacement components for specific vehicle applications and manufactured under an automotive ISO 9001/TS 16949 certified quality system. The brand has supplied engine management and fuel system components since 1946, with application-specific fitment and ECU feedback requirements in mind.