Walker 250-23121 Oxygen Sensor

Walker Products OE Oxygen Sensor for Nissan and Infiniti

Walker Products OE 250-23121 is a heated oxygen sensor built for specific upstream applications on select Nissan and Infiniti vehicles. It is engineered as an OE-style replacement to deliver the diagnostic feedback the ECU expects, helping maintain proper air-fuel control and emissions performance.

For shoppers searching for an upstream oxygen sensor for a 2000-2001 Nissan Altima, 2001 Nissan Frontier, or 2000-2001 Infiniti G20, this Walker Products OE sensor is matched to the listed position and application details.

Key Features

• Part number: 250-23121
• Heated oxygen sensor design for faster operating response
• Specific fit for the listed upstream positions
• 3-wire configuration with 20-gauge wiring
• Threaded mounting with 18.0 mm thread diameter
• Radiused polygon male connector for application-specific connection
• Wiring harness length: 12.91
• Overall length: 16.46

Product Details

Walker Products OE focuses on engine management and oxygen/air-fuel sensors built for direct replacement use. The 250-23121 oxygen sensor is designed for the exact fitment position on the vehicle, including upstream, upstream front, and left or right upstream locations where listed. This helps ensure the ECU receives the correct signal for fuel control and emissions monitoring on supported Nissan and Infiniti models.

Walker Products 250-23121 is listed for 2000-2001 Infiniti G20, 2000-2001 Nissan Altima, 2001 Nissan Frontier, 2000-2001 Nissan Maxima, and 2000-2001 Nissan Sentra in the specified upstream positions. This part cross-references Walker Products OE 250-23121 for the same application.

What It Helps Address

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

Installation Notes and Tips

Verify the exact year, model, and sensor position before ordering. Confirm whether your vehicle requires upstream front, upstream left, or upstream right placement, and compare the connector shape, wire count, and thread size to the original sensor. Inspect the sensor wiring harness and connector for damage before installation, since damaged wiring can shorten sensor life and affect operation.

Quality Assurance

Walker Products states that its engine management sensors are developed as OE replacement parts and manufactured under Automotive ISO9001/TS 16949 certification standards. Since 1946, Walker Products has supplied engine management and fuel system components for vehicle applications worldwide.