Walker 250-25159 Oxygen Sensor - Upstream

Walker OE Base Oxygen Sensor

Walker 250-25159 is a specific-fit, heated wide-band oxygen sensor built for OE-style replacement on select Nissan and Suzuki applications. It is engineered to provide the ECU with the diagnostic feedback needed for proper air-fuel control, emissions monitoring, and drivability.

Compatible with 2005-2012 Nissan Frontier upstream Bank 1 Sensor 1 and 2009 Suzuki Equator upstream Bank 1 Sensor 1, this Walker OE Base Sensor is designed around the application’s connector, thread, and terminal requirements. The Walker OE Base Sensor line focuses on direct-fit engine management sensors for vehicles that need accurate sensor feedback and consistent electrical connection.

Key Features

• Part number: 250-25159
• Heated wide-band oxygen sensor
• Specific-fit design for the listed upstream applications
• Rectangle female connector with 5-wire layout
• 6-terminal, male terminal configuration
• M18 x 1.5 thread size with 22 mm wrench size
• OE Base Sensor line for application-specific replacement

Detailed Description

Walker Products designs engine management and oxygen/air-fuel sensors as OE replacement parts for application-specific fitment and ECU feedback requirements. Walker 250-25159 is built for the upstream position on the 2005-2012 Nissan Frontier and the 2009 Suzuki Equator, where precise air-fuel sensing is critical to engine management and emissions control. If you are searching for a 2005-2012 Nissan Frontier upstream oxygen sensor or a 2009 Suzuki Equator Bank 1 Sensor 1 replacement, this part number matches those listed applications.

The OE Base Sensor line is intended for vehicles that rely on accurate sensor input to manage fuel delivery and monitor exhaust conditions. This sensor uses a heated, wide-band design with a rectangular female connector, spade terminal type, and M18 x 1.5 thread for the specified fitment. Walker 250-25159 is also referenced by part number 250-25159 for catalog and lookup purposes.

Common Issues This Sensor May Address

• Illuminated malfunction indicator light related to oxygen sensor performance
• Poor engine operation caused by incorrect air-fuel feedback
• Increased fuel consumption from inaccurate exhaust sensing
• Higher exhaust emissions from a failing upstream sensor
• Fault codes stored in the ECU for the affected sensor circuit

Installation Notes and Tips

Before replacement, inspect the sensor wiring harness and connector for heat damage, corrosion, or broken terminals. Confirm the upstream Bank 1 Sensor 1 location on the vehicle before installation, and verify thread and connector match the original sensor. For best results, clear stored fault codes after installation and confirm the repair with a scan tool.

Quality Assurance

Walker Products has produced engine management and fuel system components since 1946 and operates as an ISO 9001/TS 16949 certified company. The OE Base Sensor line is developed for application-specific replacement and consistent diagnostic feedback to the ECU. Part number 250-25159 reflects Walker’s OE-style approach for the listed Nissan Frontier and Suzuki Equator applications.