Walker 1004-1021 Nitrogen Oxide (NOx) Sensor - Turbocharger Outlet Pipe

Walker Genuine OE NOx Sensor

Walker Genuine OE NOx Sensor 1004-1021 is built for diesel and gasoline emission systems that rely on accurate nitrogen oxide monitoring. It uses OE-style connectors, a square female connector, and a 910 mm harness length for a direct replacement on specific applications, including Ford F-250 and Ford F-350 diesel emission system service where this part number is specified.

Walker Products Genuine OE line focuses on OE-level fit and sensor performance for modern aftertreatment systems. Part number 1004-1021 is engineered for selective catalytic reduction (SCR) systems where precise NOx measurement supports proper exhaust aftertreatment operation and helps protect downstream components such as diesel particulate filters.

Key Features

• Genuine OE NOx sensor for emission control service
• Specific-fit design with OE connector and harness length
• Square connector shape with gray female connector
• 4-terminal configuration with male terminals
• Matte finish and multi-colored lead design
• Built for high-heat, vibration, and corrosive exhaust environments
• Walker part number 1004-1021 for catalog and service matching

Detailed Description

This Walker NOx sensor is produced to meet the demands of current diesel aftertreatment systems and select gasoline emission platforms. Accurate NOx sensing is critical for SCR operation, emissions management, and long-term engine efficiency. The 1004-1021 sensor is manufactured to OE standards by Tier 1 OE suppliers, using the same type of materials and precision processes expected in factory-installed emission components. For technicians servicing Ford F-250 and Ford F-350 applications, this sensor supports direct replacement where the OE part number calls for 1004-1021.

This part cross-references 2872948 and 4326873 for the same application.

What It Helps Address

• NOx sensor fault codes related to emission monitoring
• SCR system performance issues caused by inaccurate exhaust readings
• Aftertreatment inefficiency that can affect diesel emissions control
• Downstream component stress from poor NOx measurement
• Drivability concerns tied to emission system faults on Ford F-250 and Ford F-350 service applications

Installation Notes and Tips

Verify connector shape, terminal count, harness length, and OE part number before installation. This is a specific-fit sensor, so confirm the vehicle application and sensor location against the service information for your Ford F-250 or Ford F-350. Inspect the harness routing and exhaust-side mounting area for heat damage, corrosion, or connector contamination before connecting the replacement sensor.

Quality Assurance

Walker Genuine OE NOx Sensors are built by Tier 1 OE suppliers and produced to OE-level material and manufacturing standards. The design is field-proven for demanding exhaust environments and supports reliable emission system service across domestic and import applications.