Bosch 15275 Oxygen Sensor - Downstream

Bosch Validated Oxygen Sensor for Downstream Control

Bosch Validated Oxygen Sensor 15275 is a specific-fit, narrow-band heated O2 sensor built for precise air-fuel-ratio feedback to the ECU. It is engineered for downstream use on select Scion xA, Scion xB, and Toyota Echo applications, helping maintain stable combustion control and lower emissions.

Key Features

• Specific-fit Bosch oxygen sensor for direct application matching
• Narrow-band heated sensor design for closed-loop fuel control
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• 4-wire harness with blade terminals and rectangular male connector
• Wiring harness included with 13.9 in harness length
• Metal housing with high-temperature-resistant construction
• Downstream position coverage for select Scion xA, Scion xB, and Toyota Echo models

Product Details

Bosch Validated Oxygen Sensor 15275 uses Bosch narrow-band sensor technology developed from decades of OE oxygen sensor engineering. The sensor measures exhaust oxygen content and sends accurate feedback to the engine control unit, supporting consistent fuel trim correction and efficient combustion. Bosch’s validated oxygen sensor line is built with ceramic sensing elements, controlled heater operation, and durable materials that hold up under heat and vibration. This part cross-references 8946552200 for the same application.

What This Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Rough idle or unstable air-fuel control from a worn downstream sensor
• Increased emissions from inaccurate exhaust oxygen readings
• Delayed closed-loop operation after sensor aging or heater degradation
• Fuel trim issues caused by slow sensor response

Installation Notes and Tips

Fits 2004-2006 Scion xA, downstream. Fits 2004-2006 Scion xB, downstream. Fits 2003-2005 Toyota Echo, downstream. Confirm connector shape, wire count, thread size, and sensor position before installation. Use the correct oxygen sensor socket for the 22 mm hex and verify the exhaust threads are clean before threading the sensor into place.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development experience. The Bosch Validated Oxygen Sensor line is built to OE-proven standards for accuracy, durability, and consistent operation in demanding exhaust environments.