Walker 250-25172 Oxygen Sensor - Upstream

Walker OE Base Sensor 250-25172

Walker OE Base Sensor 250-25172 is a specific-fit, heated wide-band oxygen sensor built for upstream use on select Mazda applications. It is engineered to provide the ECU with the diagnostic feedback needed for accurate air-fuel control, emissions monitoring, and drivability management.

For shoppers searching for an upstream oxygen sensor for a 2021-2025 Mazda 3, Mazda CX-30, Mazda CX-50, or Mazda MX-5 Miata, this Walker Products replacement is matched to the listed vehicle, position, and connector configuration. The OE Base Sensor line focuses on application-specific fitment for direct replacement service.

Key Features

• Part number 250-25172
• Specific-fit upstream oxygen sensor
• Wide-band sensor type with heated operation
• 5-wire design with female rectangle connector
• Threaded M18 x 1.5 mounting
• Standard replacement grade for OE-style service
• Wiring harness length: 315.00
• Overall length: 348.00

Product Details

Walker Products has developed the OE Base Sensor line as an application-specific replacement range for engine management systems. This oxygen sensor is built for the listed Mazda fitments and is intended to deliver the feedback the ECU uses to manage fuel delivery and emissions performance. The wide-band design, heated element, and 5-wire configuration support precise upstream sensing on modern vehicles.

Walker Products has supplied engine management and oxygen/air-fuel sensors since 1946 and manufactures electronic components under ISO 9001/TS 16949 quality systems. Part number 250-25172 is a direct-fit option for drivers and repair shops servicing a Mazda 3, Mazda CX-30, Mazda CX-50, or MX-5 Miata with the specified upstream sensor location.

What It Helps Address

• Check engine light related to upstream oxygen sensor performance
• Poor fuel economy caused by incorrect air-fuel feedback
• Rough running or hesitation from inaccurate sensor readings
• Elevated exhaust emissions from a failing sensor
• Fault codes stored in the ECU for sensor or related system issues

Installation Notes

Verify the connector shape, terminal count, thread size, and upstream position before installation. Inspect the sensor wiring harness and connector for physical damage, since damaged wiring can shorten service life and affect sensor operation. Confirm the vehicle application against the listed fitment for 2021-2025 Mazda 3, 2021-2025 Mazda CX-30, 2023-2025 Mazda CX-50, and 2022-2025 Mazda MX-5 Miata.

• Fits 2021-2025 Mazda 3, Upstream
• Fits 2021-2025 Mazda CX-30, Upstream
• Fits 2023-2025 Mazda CX-50, Upstream
• Fits 2022-2025 Mazda MX-5 Miata, Upstream

Quality Assurance

Walker Products manufactures this OE Base Sensor replacement under established automotive quality systems and application-specific engineering standards. Part number 250-25172 is built for the listed Mazda upstream oxygen sensor applications and the corresponding ECU feedback requirements.