Bosch 15121 Oxygen Sensor - Downstream Left

Reliable Oxygen Sensor for Lexus GS300

The Bosch Validated Oxygen Sensor 15121 is designed specifically for the Lexus GS300, ensuring precise emission control and optimal engine performance. This narrow-band heated oxygen sensor offers a direct fit with a 37.4-inch wiring harness and a threaded mounting type for secure installation.

• Compatible with Lexus GS300 models
• Part number 15121 for exact replacement
• Narrow-band heated oxygen sensor type
• 37.4-inch wiring harness length with 4 wires
• Threaded mounting with 18 mm thread diameter
• Blade terminal type with 4 male terminals
• Rectangle-shaped male connector
• Steel housing with 22 mm hex size
• Overall length of 41.1 inches

About the Bosch Validated Oxygen Sensor Line

The Bosch Validated Oxygen Sensor product line focuses on delivering sensors that meet strict quality and performance standards. These sensors are engineered to provide accurate air-fuel mixture readings, helping maintain emission compliance and engine efficiency. The 15121 sensor is part of this line, offering a standard replacement solution with a heated narrow-band design tailored for specific vehicle applications like the Lexus GS300.

Product Details and Specifications

This Bosch oxygen sensor features a heated narrow-band sensor type, which allows for faster warm-up times and improved emission control. The sensor includes a 37.4-inch wiring harness with four wires and blade terminals, ensuring a secure electrical connection. The connector is male with a rectangular shape, designed for a specific fit rather than universal compatibility. The sensor’s metal housing is finished in steel and includes a 22 mm hex size for installation using standard tools. The threaded mounting type with an 18 mm thread diameter ensures a precise and secure fit in the exhaust system.

Common Applications and Issues Addressed

• Restores accurate oxygen sensing for Lexus GS300 emission systems
• Helps resolve engine performance issues related to faulty oxygen sensors
• Reduces rough idling and poor fuel economy caused by sensor failure
• Assists in passing emissions inspections by maintaining proper air-fuel ratios
• Prevents check engine light triggers related to oxygen sensor faults

Installation Notes and Tips

When installing the Bosch Validated Oxygen Sensor 15121, ensure the vehicle is cool to avoid burns. Use a 22 mm oxygen sensor socket for removal and installation. Verify the connector orientation matches the original sensor’s rectangular male connector to avoid wiring issues. The threaded mounting requires careful tightening to manufacturer torque specifications to prevent exhaust leaks or sensor damage. This sensor is a specific fit for the Lexus GS300, so confirm vehicle compatibility before installation.

Quality Assurance and Warranty

Bosch oxygen sensors are manufactured to meet OEM standards for durability and performance. The Validated Oxygen Sensor line undergoes rigorous testing to ensure reliable operation under various driving conditions. This part is a standard replacement grade sensor designed to maintain emission control system integrity. Warranty details are provided by Bosch and typically cover defects in materials and workmanship.