Bosch 15569 Oxygen Sensor - Downstream or Downstream Left

Bosch Oxygen Sensor for Stable Fuel Control

Bosch Engineered Oxygen Sensor 15569 is a narrow-band heated O2 sensor built for precise air-fuel-ratio feedback to the ECU. It supports closed-loop operation, helps maintain stable combustion control, and is engineered for specific-fit replacement on select Toyota, Lexus, and Scion applications.

Key Features

• Specific-fit Bosch oxygen sensor for direct replacement use
• Narrow-band heated design for faster light-off and quicker closed-loop response
• 4-wire harness with square connector and blade terminals
• Threaded mounting with 18 mm thread size and 22 mm hex size
• Wiring harness included with 11.6 in harness length
• Metal housing and high-temperature-resistant construction for demanding exhaust conditions
• OE-developed Bosch Engineered Oxygen Sensor line backed by decades of oxygen sensor engineering

Product Details

Bosch 15569 uses a switching-type narrow-band sensor element to measure exhaust oxygen content and send accurate feedback to the engine control unit. That signal helps the ECU adjust fuel delivery during normal driving, cold starts, and warm operating conditions. The Bosch Engineered Oxygen Sensor line builds on Bosch’s long OE development history, including early thimble-style sensors and later planar narrowband designs that improved response time and lambda accuracy.

This part cross-references 8946512A40 and 8946548170 for the same application. It is a direct replacement choice for drivers searching for a downstream oxygen sensor for 2004-2007 Toyota Highlander, a downstream left O2 sensor for 2004-2006 Lexus RX330, or a downstream left oxygen sensor for 2004-2006 Toyota Sienna. It also serves 2016 Scion iM downstream and 2017-2018 Toyota Corolla iM downstream applications.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Unstable air-fuel ratio feedback to the ECU
• Delayed closed-loop operation after startup
• Reduced emissions control from a worn downstream sensor
• Rough combustion control caused by inaccurate exhaust oxygen readings

Installation Notes

Verify the connector shape, terminal count, thread diameter, and sensor position before installation. This Bosch oxygen sensor is threaded and heated, with a square male connector and 4-wire harness. Confirm the vehicle uses a downstream or downstream left location as listed in the fitment data, and compare the original sensor length and harness routing to the replacement part before final installation.

Quality Assurance

Bosch supplies oxygen sensors with OE-level engineering and durable materials selected for high heat and vibration exposure. Bosch 15569 is part of the Bosch Engineered Oxygen Sensor line, developed from decades of original equipment sensor design and aftermarket replacement experience.