Bosch 17250 Oxygen Sensor - Upstream

Bosch Wideband O2 Sensor for BMW M5 and M8

Bosch 17250 is an Actual OE Oxygen Sensor built as a wideband air-fuel sensor for precise upstream mixture monitoring. It delivers the detailed signal the ECU needs for accurate fuel control, stable drivability, and lower emissions in demanding BMW applications.

Designed for specific fitment, Bosch 17250 matches the factory-style threaded mounting, heated operation, and 5-wire configuration used on select BMW M5, BMW M8, and BMW M8 Gran Coupe models.

Key Features

• Wideband A/F oxygen sensor for continuous air-fuel ratio measurement across the full lambda range
• Upstream sensor position for direct feedback to the engine management system
• Heated design for faster sensor activity and improved cold-start response
• Specific-fit replacement with included wiring harness
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Oblong male connector with blade terminals and 6 terminal positions
• Robust metal housing for standard replacement service

Product Details

Bosch pioneered the planar pump-cell wideband design that became the standard for modern engine control, and this sensor reflects that OE development background. Bosch 17250 is engineered for accurate upstream readings on BMW performance models, including the M5, M8, and M8 Gran Coupe, where precise fuel-trim control matters under changing load and temperature conditions. This part cross-references BMW 11788043677 for the same application.

What This Sensor Helps Address

• Rich or lean air-fuel ratio readings that trigger drivability concerns
• Check engine lights related to upstream oxygen sensor performance
• Rough idle, hesitation, or inconsistent throttle response
• Reduced fuel economy caused by inaccurate mixture feedback
• Elevated emissions from poor fuel control

Installation Notes

Fits 2018-2020 BMW M5, Upstream. Fits 2020-2025 BMW M8, Upstream. Fits 2020-2025 BMW M8 Gran Coupe, Upstream. Use the existing threaded mounting location and verify connector shape, wire count, and sensor position before installation. Because this is a wideband sensor, correct placement and secure harness routing are important for reliable signal output.

Quality Assurance

Bosch supplies OE-level oxygen sensors backed by more than five decades of engine-management development. Bosch 17250 is built to the same standard expected in modern BMW emission-control systems and is intended for direct replacement service on the listed applications.