Bosch 15377 Oxygen Sensor - Downstream Right

Bosch Actual OE Oxygen Sensor for 2001 INFINITI QX4

Bosch 15377 is a specific-fit, narrow-band heated oxygen sensor for the downstream right position on the 2001 INFINITI QX4, Early Production. It measures exhaust oxygen content and sends air-fuel-ratio data to the ECU for closed-loop fuel control and emissions monitoring.

Built on Bosch Actual OE Oxygen Sensor engineering, this replacement uses a threaded metal housing, square connector, 4-wire harness, and blade terminals for a direct-style service part. Bosch 15377 is a practical choice for INFINITI QX4 downstream right oxygen sensor replacement when the original sensor response has slowed or the heater circuit is no longer performing correctly.

Key Features

• Specific-fit oxygen sensor for the 2001 INFINITI QX4, downstream right
• Bosch Actual OE Oxygen Sensor line with OE-based design and calibration
• Narrow-band heated sensor for closed-loop fuel control
• 4-wire configuration with included wiring harness
• Threaded 18 mm mounting with 22 mm hex size
• Square male connector and blade terminals
• Metal housing for high-temperature exhaust service

Product Details

Bosch 15377 is a switching-type oxygen sensor that reports exhaust oxygen levels to the engine control unit so the system can maintain stable combustion control. Bosch developed this sensor family from its original OE oxygen sensor work and later narrowband planar designs, focusing on faster light-off, accurate lambda feedback, and quicker closed-loop operation. For drivers searching for a 2001 INFINITI QX4 downstream right oxygen sensor or Bosch 15377 oxygen sensor replacement, this part matches the listed application and service position.

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
• Slow or inaccurate air-fuel-ratio feedback
• Rough idle or unstable fuel control from a worn sensor
• Reduced emissions performance from an aging downstream sensor
• Heater circuit faults in a heated narrow-band O2 sensor

Installation Notes

Verify the downstream right location before installation on the 2001 INFINITI QX4, Early Production. Confirm connector shape, wire count, thread diameter, and harness length against the original sensor before removal. Use proper oxygen sensor service tools for the 18 mm threaded body and avoid contaminating the sensing element during handling.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development in oxygen sensing technology. The Actual OE Oxygen Sensor line is built to deliver OE-proven fit, response, and durability for emission control service.