Walker 250-25173 Oxygen Sensor - Upstream

OE Base Oxygen Sensor for Toyota Yaris

Walker OE Base Sensor 250-25173 is a specific-fit wide-band oxygen sensor for the 2020 Toyota Yaris, upstream position. It is built as an OE-style replacement to deliver the diagnostic feedback the ECU expects from the air-fuel monitoring system.

For a 2020 Toyota Yaris upstream oxygen sensor replacement, this Walker sensor is engineered for the correct application, connector style, and mounting location. The 250-25173 part number is also referenced as Walker 250-25173 for buyers searching by OE replacement number.

Key Features

• Specific-fit oxygen sensor for the upstream location
• Wide-band sensor type for modern engine management systems
• Heated design for faster operating response
• 5-wire configuration with 5 terminals
• Rectangle female connector with male spade terminals
• M18 x 1.5 threaded mounting with 22 mm wrench size
• Wiring harness length: 540.00
• Overall length: 573.00

Product Details

Walker Products develops engine management and oxygen/air-fuel sensors as OE replacement parts for a wide range of vehicles. This OE Base Sensor line focuses on application-specific fitment, so the sensor matches the vehicle position and provides the ECU with the required feedback for proper fuel control and emissions monitoring. The 250-25173 oxygen sensor is a direct-fit solution for the 2020 Toyota Yaris, upstream, and is suited for drivers replacing a failed sensor that has triggered fault codes or drivability concerns.

Walker 250-25173 is a practical choice when you need a 2020 Toyota Yaris upstream oxygen sensor replacement with the correct connector, thread size, and sensor configuration. The OE Base Sensor line is built around exact application coverage rather than universal fitment, which helps simplify parts selection for emission control repairs.

What It Helps Address

• Check engine light or malfunction indicator light related to oxygen sensor faults
• Poor fuel economy caused by inaccurate air-fuel feedback
• Rough running or inconsistent engine performance
• Elevated exhaust emissions from a failing upstream sensor
• Diagnostic trouble codes stored in the ECU for sensor or related system issues

Installation Notes

Confirm the upstream position, connector shape, wire count, thread size, and overall sensor length before installation. Inspect the sensor wiring harness and connector for physical damage, since damaged wiring can shorten sensor life and affect readings. Verify the mounting threads are clean and that the sensor seats correctly in the threaded bung.

For best results, compare the removed part to Walker 250-25173 and confirm the vehicle is a 2020 Toyota Yaris with the upstream sensor location specified in the fitment data.

Quality Assurance

Walker Products has manufactured engine management and fuel system components since 1946 and operates as an ISO 9001/TS 16949 certified company. The OE Base Sensor line is built to support application-specific replacement needs for modern emissions and engine control systems.