Walker 250-21035 Oxygen Sensor - Upstream

Walker Products OE Oxygen Sensor for Mazda Miata

Walker Products OE Part Number 250-21035 is a specific-fit oxygen sensor engineered for upstream placement and direct ECU feedback. It is built for 1990-1993 Mazda Miata applications where accurate exhaust monitoring is needed to help maintain proper engine management.

Walker Products OE focuses on original-equipment-style replacement sensors for exact application fitment. This oxygen sensor uses a threaded mount, female radiused polygon connector, and a 19.41-inch wiring harness length to match the vehicle’s sensor location and electrical connection requirements.

Key Features

• Specific-fit oxygen sensor for upstream installation
• Fits 1990-1993 Mazda Miata, upstream
• Walker Products OE Part Number 250-21035
• Non-heated sensor design
• 18.0 mm thread diameter with threaded mounting type
• Female radiused polygon connector
• 20-gauge wire with 19.41-inch harness length
• Overall length: 22.95 inches

Detailed Description

This Walker Products OE oxygen sensor is built for upstream exhaust monitoring on 1990-1993 Mazda Miata models. As an OE-style replacement, it is made for the specified application and position so the ECU receives the expected sensor feedback for fuel control and emissions management. Part number 250-21035 is a direct-fit option for drivers replacing a worn or failed upstream oxygen sensor on the Mazda Miata.

Walker Products has supplied engine management and oxygen/air-fuel sensors for decades, with product development centered on application-specific fitment and connector configuration. For Mazda Miata owners searching for an upstream oxygen sensor, front oxygen sensor, or OE replacement sensor for 1990-1993 models, this part number 250-21035 matches the listed vehicle coverage.

What This Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Poor engine operation caused by incorrect exhaust feedback
• Increased fuel consumption from inaccurate air-fuel control
• Higher exhaust emissions from a failing upstream sensor
• Fault codes stored in the ECU for sensor-related issues

Installation Notes and Tips

Confirm the sensor position before ordering: this part is listed for upstream use only. Verify connector shape, thread diameter, wire length, and harness routing against the original sensor on the vehicle. Inspect the sensor wiring harness and connector for damage before installation, since physical wear can shorten sensor life and affect operation.

Fits 1990-1993 Mazda Miata, upstream. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

Quality Assurance

Walker Products OE sensors are developed as original-equipment replacement parts for specific vehicle applications and positions. Walker Products is an automotive ISO 9001/TS 16949 certified company, and its engine management sensor line is built around application-specific fitment and ECU feedback requirements.