Bosch 17231 Oxygen Sensor - Upstream

Bosch Wideband OE Oxygen Sensor for BMW

Bosch 17231 is an Actual OE Oxygen Sensor built as a wideband air-fuel sensor for precise mixture feedback to the engine control unit. It is a specific-fit, heated upstream sensor with a 5-wire harness and 6-terminal connection, made for accurate control on select BMW applications.

Fits 2011 BMW 528i, upstream. Fits 2011-2012 BMW X3, upstream. This Bosch wideband sensor is also referenced by part number 17231 for OE-style replacement needs on these vehicles.

Key Features

• Wideband A/F oxygen sensor for continuous air-fuel ratio measurement
• Heated design for faster sensor response and stable operation
• Specific-fit replacement with included wiring harness
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Metal housing with robust ceramic sensor construction
• Oblong male connector, blade terminals, and 30.7 in wiring harness length

Product Details

Bosch 17231 is part of the Bosch Actual OE Oxygen Sensor line, which focuses on OE-proven sensor design for modern engine management systems. As a wideband sensor, it provides more detailed feedback than a traditional switching O2 sensor, helping the ECU maintain accurate air-fuel control across changing load and temperature conditions. That makes it a direct-fit choice for BMW X3 and BMW 528i upstream applications where precise sensor input matters for drivability and emissions control.

Built with optimized heater control and fast light-off characteristics, this sensor is suited to demanding thermal cycles and rapid throttle changes. The 18 mm threaded mount, 34.1 in overall length, and 32.9 in sealing-surface-to-connector length support OE-style replacement on the listed BMW applications.

What It Helps Address

• Check engine light related to upstream oxygen sensor performance
• Rough idle or inconsistent air-fuel correction
• Reduced fuel economy from inaccurate mixture feedback
• Emissions test failures tied to sensor response issues
• Slow sensor switching or delayed closed-loop operation

Installation Notes and Tips

Confirm the upstream location and connector style before installation. Use the correct 22 mm oxygen sensor socket, and inspect the harness routing so the lead is kept clear of exhaust heat and moving components. Verify thread size and connector orientation against the original sensor before final tightening.

Quality Assurance

Bosch has more than five decades of OE sensor development and supplies aftermarket oxygen sensors built to OE-level specifications. Bosch 17231 reflects that OE-focused engineering for the listed BMW 528i and BMW X3 applications.