Bosch 17099 Oxygen Sensor - Upstream or Upstream Rear

Bosch Wideband OE Oxygen Sensor

Bosch 17099 is an Actual OE wideband air-fuel oxygen sensor built for precise mixture feedback and stable engine management. It uses a heated, wide-band design with a 5-wire harness and 6-terminal blade connection for direct replacement on select BMW applications.

For BMW 128i, 328i, 323i, 325i, 330i, 528i, X3, and Z4 applications, this sensor provides the ECU with continuous air-fuel ratio data across the full lambda range. Bosch’s wideband sensor design supports accurate control during cold starts, rapid throttle changes, and high-temperature operation.

Key Features

• Wide-band oxygen sensor for continuous air-fuel ratio measurement
• Heated design for faster light-off and improved response
• Specific-fit replacement with oblong male connector
• 5-wire harness included for direct installation
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Metal housing and ceramic sensor construction for durability
• Actual OE Oxygen Sensor from Bosch OE development

Product Details

Bosch 17099 is part of the Bosch Actual OE Oxygen Sensor line, which focuses on OE-style fit, sensor accuracy, and dependable signal quality. Bosch pioneered the first wideband A/F oxygen sensor and the planar pump-cell design now used widely in modern engine management. This sensor is engineered to deliver detailed feedback to the ECU so the engine can maintain the correct air-fuel ratio under changing load and temperature conditions. This part cross-references URO 11787558073 for the same application.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn upstream sensor
• Rough idle or hesitation caused by inaccurate mixture feedback
• Reduced fuel economy from poor fuel control
• Emissions test failure tied to sensor response or signal quality

Installation Notes and Fitment

Fits 2008-2013 BMW 128i, Upstream; Fits 2008-2012 BMW 128i, Upstream Rear; Fits 2007-2013 BMW 328i, Upstream; Fits 2007-2013 BMW 328i, Upstream Rear; Fits 2013 BMW 328i, Upstream Rear; Fits 2009-2013 BMW 328i xDrive, Upstream Rear; Fits 2009-2012 BMW 328i xDrive, Upstream Rear; Fits 2007-2011 BMW 323i, Upstream; Fits 2006-2011 BMW Z4, Upstream; Fits 2008-2010 BMW 528i, Upstream; Fits 2009-2010 BMW 528i xDrive, Upstream; Fits 2007-2010 BMW X3, Upstream; Fits 2007-2008 BMW 328xi, Upstream; Fits 2007-2008 BMW 328xi, Upstream Rear; Fits 2008 BMW 528xi, Upstream; Fits 2007 BMW 525i, Upstream; Fits 2007 BMW 525xi, Upstream; Fits 2007 BMW 530i, Upstream; Fits 2007 BMW 530xi, Upstream; Fits 2006 BMW 323i, Upstream; Fits 2006 BMW 325i, Upstream; Fits 2006 BMW 325xi, Upstream; Fits 2006 BMW 330i, Upstream; Fits 2006 BMW 330xi, Upstream; Fits 2006 BMW 525i, Upstream; Fits 2006 BMW 525xi, Upstream; Fits 2006 BMW 530i, Upstream; Fits 2006 BMW 530xi, Upstream.

Verify connector shape, harness routing, and sensor position before installation. This is a specific-fit, threaded sensor with a 35.2 in sealing-surface-to-connector length and 36.4 in overall length, so routing should match the original layout on the vehicle.

Quality Assurance

Bosch supplies OE-developed oxygen sensors to the aftermarket with the same focus on accuracy, durability, and emissions control used in original equipment applications. Bosch 17099 is built for consistent signal output and reliable operation in demanding thermal conditions.