Bosch 15957 Oxygen Sensor - Downstream Left

Bosch OE Oxygen Sensor for Nissan

Bosch 15957 is an actual OE-style narrow-band heated oxygen sensor built for precise air-fuel ratio feedback to the ECU. It is a direct-fit replacement for select Nissan Frontier and Nissan Xterra applications, including downstream left positions, with the connector, harness length, and threaded mounting style needed for a proper service replacement.

Key Features

• Actual OE Oxygen Sensor from Bosch
• Narrow-band heated sensor for closed-loop fuel control
• Specific-fit design with 4-wire harness and square male connector
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Wiring harness included for direct replacement service
• Metal housing and high-temperature-resistant construction
• Fits 1999-2003 Nissan Frontier, downstream left
• Fits 2000-2003 Nissan Xterra, downstream left

Product Details

Bosch 15957 uses a switching-type narrow-band design to measure exhaust oxygen content and send accurate feedback to the engine control unit. Bosch developed this sensor line from its original OE oxygen sensor technology and later planar narrowband designs, focusing on faster light-off, stable lambda control, and consistent operation under heat and vibration. For Nissan Frontier and Nissan Xterra owners, this Bosch oxygen sensor supports accurate downstream monitoring and OE-style service replacement.

This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Rough or unstable closed-loop fuel control
• Emissions test failures tied to sensor response issues
• Delayed sensor switching or degraded exhaust monitoring

Installation Notes

Verify the downstream left location before installation and confirm the 4-wire square connector matches the original sensor. Use the 18 mm thread size and 22 mm hex specification to select the correct removal and installation tools. Inspect the harness routing and connector condition during replacement to help prevent wiring strain or exhaust heat damage.

Quality Assurance

Bosch supplies this oxygen sensor as an OE-proven replacement backed by more than five decades of oxygen sensor development and aftermarket support. Bosch 15957 is engineered to deliver consistent signal accuracy and durable operation in demanding thermal and vibration conditions.