VDO Gauges 5WK9639Z Secondary Air Injection Mass Air Flow Sensor

The VDO 5WK9639Z is a secondary air injection mass air flow sensor designed specifically for BMW vehicles equipped with M54 and S85 engines. This OE-quality sensor is manufactured by Continental/VDO, a trusted supplier to automotive manufacturers worldwide for nearly a century.

Important Note: This sensor is for the secondary air injection system, not the primary intake air mass meter. The secondary air injection system is critical for reducing emissions during cold starts by injecting fresh air into the exhaust stream.

Key Features:

• OEM-quality construction ensuring exact fit and function
• Direct replacement for BMW part numbers 11721438814 and 11727521727
• Precise air mass measurement for optimal secondary air injection operation
• Essential for emissions compliance and engine health
• Manufactured by Continental/VDO with proven OE reliability

This sensor plays a vital role in your BMW's emissions control system by accurately measuring airflow in the secondary air injection circuit. Proper function ensures efficient cold-start emissions reduction and maintains compliance with environmental regulations.

Cross-Reference Numbers: BMW 11721438814, 11727521727, 1438814, 7521727; Delphi AF10451-11B1; ERA 558121; HELLA 8ET 009 142-611; MEAT & DORIA 86270