Walker 250-21026 Oxygen Sensor - Upstream

OE Oxygen Sensor for Specific Applications

Walker Products OE 250-21026 is a specific-fit oxygen sensor engineered as an OE-style replacement for select Ford and Mazda applications. It is built for upstream placement and provides the ECU with the feedback needed to monitor exhaust oxygen levels and engine management performance.

This Walker Products OE oxygen sensor is a direct-fit option for 1994-1997 Ford Aspire, upstream, and 1989-1991 Mazda RX-7, upstream. The 250-21026 uses a threaded mounting design, a male radiused polygon connector, and a 12.32-inch wiring harness for application-specific installation.

Key Features

• Walker Products OE part number 250-21026
• Specific-fit oxygen sensor for upstream placement
• Non-heated sensor type
• 18.0 mm thread diameter with threaded mounting
• Male radiused polygon connector
• 12.32-inch wiring harness length
• 20-gauge wire construction with 1 wire
• Compatible with select Ford Aspire and Mazda RX-7 applications

Product Details

Walker Products OE sensors are developed as Original Equipment replacement parts for vehicle-specific applications. This oxygen sensor is designed to deliver the diagnostic feedback required by the ECU on the listed vehicles, helping maintain proper fuel control and emissions monitoring. The 250-21026 is a non-heated upstream oxygen sensor for 1994-1997 Ford Aspire and 1989-1991 Mazda RX-7 models.

Walker Products has supplied engine management and oxygen/air-fuel sensors since 1946, and its OE line focuses on application-specific fitment and connector design. If you are replacing a failed upstream sensor on a Ford Aspire or Mazda RX-7, part number 250-21026 provides a direct-fit service solution.

This part cross-references no listed aftermarket interchange numbers for the same application.

What It Helps Address

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

Installation Notes

Verify the connector shape, thread diameter, and upstream position before installation. Inspect the sensor wiring harness and connector for damage, since physical wear can shorten service life and affect signal quality. Confirm the vehicle application by year, make, model, and sensor location before ordering the 250-21026.

Quality Assurance

Walker Products OE sensors are manufactured for specific vehicle applications and built to provide the diagnostic feedback expected by the ECU. The brand operates under Automotive ISO9001/TS 16949 certification and focuses on OE-style replacement coverage for engine management and emissions systems.