Bosch 16809 Oxygen Sensor - Downstream

Bosch Actual OE Oxygen Sensor for BMW

Bosch 16809 is a narrow-band heated oxygen sensor built for precise air-fuel ratio feedback to the ECU. It supports stable combustion control and emissions management for select BMW applications, including downstream service on 2006-2010 BMW 323i, 525i, 525xi, 528i, 528i xDrive, 528xi, 530i, and 530xi models.

The Bosch Actual OE Oxygen Sensor line reflects Bosch’s long OE development history, with switching-type sensor technology, advanced ceramic elements, and optimized heater control for consistent signal response under demanding thermal and vibration conditions. This Bosch 16809 oxygen sensor uses a threaded mounting design, 4-wire configuration, and a round female connector with included wiring harness for direct replacement service.

Key Features

• Actual OE oxygen sensor for select BMW downstream applications
• Narrow-band heated sensor for closed-loop fuel control
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• 4-wire design with round female connector and pin terminals
• Specific-fit replacement with wiring harness included
• Metal housing and steel finish for underbody service conditions
• Bosch part number 16809

Product Details

Bosch 16809 is engineered as a standard replacement oxygen sensor for vehicles that rely on accurate downstream exhaust feedback. It measures oxygen content in the exhaust stream so the engine control unit can maintain the proper air-fuel mixture and monitor catalyst performance. For BMW 528i downstream oxygen sensor replacement, BMW 530i downstream oxygen sensor service, and BMW 323i downstream oxygen sensor repair, this Bosch sensor provides the OE-style fit and signal behavior expected in factory applications.

This part cross-references BMW 11787544655 for the same application. Bosch’s Actual OE Oxygen Sensor line is backed by more than five decades of OE development, and the design uses high-temperature-resistant materials to maintain performance in harsh exhaust environments.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings at the ECU
• Rough idle or unstable combustion control from faulty exhaust feedback
• Emissions test failure caused by a degraded downstream sensor
• Slow closed-loop response after sensor aging or contamination

Installation Notes and Tips

• Fits 2008-2010 BMW 528i, downstream
• Fits 2009-2010 BMW 528i xDrive, downstream
• Fits 2006-2009 BMW 323i, downstream
• Fits 2008 BMW 528xi, downstream
• Fits 2006-2007 BMW 525i, downstream
• Fits 2006-2007 BMW 525xi, downstream
• Fits 2006-2007 BMW 530i, downstream
• Fits 2006-2007 BMW 530xi, downstream

Confirm the connector style, harness routing, and downstream sensor location before installation. Use the correct oxygen sensor socket for the 22 mm hex, and verify the threaded seat is clean before tightening the sensor to specification.

Quality Assurance

Bosch supplies OE-proven oxygen sensor technology to the aftermarket, using the same development experience that supports vehicle manufacturers. Bosch 16809 is built for specific-fit replacement on select BMW applications and is backed by Bosch’s long-standing OE engineering focus.