Bosch 16239 Oxygen Sensor - Downstream

Bosch OE Downstream Oxygen Sensor

Bosch Actual OE Oxygen Sensor 16239 is a narrow-band heated downstream O2 sensor built for precise air-fuel-ratio feedback and stable closed-loop control. It is a specific-fit replacement for select BMW applications, including BMW 320i, 328i, X3, X5, and Z4 models.

• Specific-fit Bosch oxygen sensor for downstream placement
• Narrow-band heated design for faster light-off and quicker closed-loop operation
• 4-wire configuration with included wiring harness
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Metal housing with high-temperature-resistant construction
• Connector shape: rectangle; connector gender: male
• Wire length: 21.3 in; harness length: 18.3 in

OE-Style Sensor Design

Bosch developed this Actual OE Oxygen Sensor line from decades of original equipment engineering, using ceramic sensing elements and controlled heater performance to deliver consistent signal accuracy under heat and vibration. Part number 16239 is a narrow-band heated sensor intended for downstream exhaust monitoring on BMW 228i, 328i, 428i, 528i, X1, X3, X4, X5, and Z4 applications listed below. This part cross-references URO 11787589122 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Slow or unstable downstream sensor response
• Incorrect air-fuel feedback affecting emissions control
• Rough combustion control caused by aging sensor output
• Failed emissions inspection tied to sensor fault codes

Installation Notes

Verify the threaded mounting location, connector style, and downstream position before installation. Use the 18 mm thread size and 22 mm hex specification to confirm fitment, and route the harness to match the original layout on the vehicle. Fits 2013-2018 BMW 320i, downstream; Fits 2013-2018 BMW 320i xDrive, downstream; Fits 2015-2018 BMW X4, downstream; Fits 2016-2018 BMW X5, downstream; Fits 2013-2017 BMW X3, downstream; Fits 2014-2016 BMW 228i, downstream; Fits 2015-2016 BMW 228i xDrive, downstream; Fits 2012-2016 BMW 328i, downstream; Fits 2014-2016 BMW 328i GT xDrive, downstream; Fits 2013-2016 BMW 328i xDrive, downstream; Fits 2014-2016 BMW 428i, downstream; Fits 2015-2016 BMW 428i Gran Coupe, downstream; Fits 2014-2016 BMW 428i xDrive, downstream; Fits 2015-2016 BMW 428i xDrive Gran Coupe, downstream; Fits 2012-2016 BMW 528i, downstream; Fits 2012-2016 BMW 528i xDrive, downstream; Fits 2012-2016 BMW Z4, downstream; Fits 2012-2015 BMW X1, downstream.

Quality Assurance

Bosch backs this oxygen sensor with OE development experience and materials selected for durability in high-temperature exhaust environments. The Bosch 16239 is built to deliver consistent sensor output and dependable emissions-system performance across the listed BMW fitments.