Bosch 15638 Oxygen Sensor - Downstream

Reliable Oxygen Sensor for Subaru Impreza, Legacy, and Outback

The Bosch Validated Oxygen Sensor 15638 is designed specifically for select Subaru models, including the Impreza, Legacy, and Outback. This narrow-band heated oxygen sensor ensures accurate air-fuel mixture readings to support optimal engine performance and emissions control.

• Specific fit for Subaru Impreza, Legacy, and Outback
• Narrow-band heated oxygen sensor with 4-wire design
• Threaded mounting type with 18 mm thread diameter and 22 mm hex size
• Includes 15-inch wiring harness with female rectangular connector
• Durable metal housing finished in steel for long-lasting use
• Standard replacement grade for reliable emission control

About the Bosch Validated Oxygen Sensor Product Line

The Bosch Validated Oxygen Sensor line focuses on providing precise and reliable sensors that meet OEM specifications. This product line is engineered to deliver consistent performance and durability, making it suitable for emission control systems in specific vehicle applications. The 15638 sensor is part of this line, ensuring compatibility and quality for Subaru vehicles requiring a narrow-band heated oxygen sensor.

Detailed Product Description and Specifications

The Bosch 15638 oxygen sensor features a narrow-band heated design with four wires, allowing for faster sensor warm-up and accurate oxygen level detection. It has a threaded mounting type with an 18 mm thread diameter and a 22 mm hex size for easy installation. The sensor includes a 15-inch wiring harness with a female rectangular connector and four female terminals, ensuring a secure and precise electrical connection. Constructed with a metal housing finished in steel, this sensor is built to withstand harsh engine conditions. The overall length measures 18.7 inches, with 17.5 inches from the sealing surface to the end of the connector, providing ample length for proper fitment in the exhaust system.

Common Applications and Issues Addressed

• Restores accurate air-fuel ratio readings for Subaru Impreza, Legacy, and Outback
• Helps resolve check engine light triggers related to oxygen sensor faults
• Improves fuel efficiency by ensuring proper combustion control
• Reduces harmful emissions by maintaining optimal sensor performance
• Prevents engine performance issues caused by faulty oxygen sensors

Installation Notes and Tips

When installing the Bosch 15638 oxygen sensor, ensure the engine and exhaust system are cool to avoid burns. Use a 22 mm oxygen sensor socket for removal and installation. Verify the wiring harness length and connector type match your vehicle’s specifications. Avoid over-tightening the sensor to prevent thread damage. Since this sensor is a specific fit for Subaru Impreza, Legacy, and Outback models, confirm compatibility with your vehicle’s year and engine type before installation.

Quality Assurance and Warranty

The Bosch Validated Oxygen Sensor 15638 is manufactured to meet strict quality standards for emission control components. It is designed as a standard replacement part to provide reliable performance and durability. Bosch products typically come with a limited warranty covering defects in materials and workmanship; please refer to Bosch’s official warranty policy for detailed terms.