Bosch 17208 Oxygen Sensor - Upstream Left or Upstream Right

Bosch Wideband OE Oxygen Sensor

Bosch 17208 is an Actual OE Oxygen Sensor built as a wideband air-fuel sensor for precise mixture feedback to the ECU. It is a direct-fit replacement for select BMW applications, including 2002-2005 BMW 745i and 745Li, 2004-2006 BMW 760i, and 2003-2006 BMW 760Li.

Key Features

• Wideband A/F oxygen sensor for continuous air-fuel ratio measurement across the full lambda range
• Heated design with optimized heater control for faster sensor response
• Specific-fit replacement with 5-wire harness and 6 terminals
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Oblong male connector with included wiring harness
• Robust metal housing and ceramic sensor construction for thermal durability
• Direct OE-style replacement for BMW 545i, 645Ci, 745i, 745Li, 760i, and 760Li applications

Product Details

Bosch pioneered the wideband planar pump-cell oxygen sensor design that is now widely used in modern engine management systems. Bosch 17208 follows that OE development path with fast light-off, stable heater performance, and detailed signal output that helps the engine control module manage fuel delivery more accurately than a traditional switching sensor. This Bosch Actual OE Oxygen Sensor is a standard replacement part for upstream left and upstream right positions on the listed BMW models, including BMW 760i, BMW 760Li, BMW 545i, BMW 645Ci, BMW 745i, and BMW 745Li. This part cross-references BMW 11787521705 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn wideband sensor
• Reduced fuel economy caused by inaccurate exhaust feedback
• Rough engine operation from delayed or unstable sensor response
• Emission test failures tied to faulty upstream oxygen sensor data

Installation Notes

Compatible With 2002-2005 BMW 745i, upstream right; 2002-2005 BMW 745Li, upstream right; 2004-2005 BMW 545i, upstream left; 2004-2005 BMW 645Ci, upstream left; 2004-2006 BMW 760i, upstream left; and 2003-2006 BMW 760Li, upstream left. Verify connector shape, thread size, and sensor position before installation. Use the existing threaded mounting point and route the harness to match the original layout.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development experience. The 17208 is built to Bosch OE standards for accurate signal output, reliable heater control, and durable operation in demanding thermal conditions.