Rear Oxygen Sensor for BMW 7 Series (2009) This product is a rear oxygen sensor designed for BMW 7 Series vehicles from 2009. It measures the oxygen content in the exhaust after the catalytic converter and provides a feedback signal to the engine control unit to help regulate the air–fuel ratio. Proper operation of the rear sensor supports engine efficiency, emissions control, and overall drivability. Key benefits Restores accurate oxygen readings to support correct air–fuel ratio adjustments by the engine control unit. Helps maintain catalytic converter efficiency and reduce emissions by providing reliable exhaust data. Supports engine performance and fuel economy by enabling proper fuel trimming and combustion control. Reduces the likelihood of diagnostic trouble codes and check engine light issues caused by a faulty rear O2 sensor. Intended as a replacement part for BMW 7 Series models from 2009, promoting smooth operation and longterm reliability. Key attributes Functionality: rear oxygen sensor that monitors exhaust gas composition to control the vehicle's air–fuel ratio. Compatibility: specifically designed for BMW 7 Series vehicles with model year 2009. Verify fitment with your vehicle's VIN or part number to ensure compatibility. Size: standard rear O2 sensor size used in BMW applications; exact dimensions may vary by sensor model—refer to the product datasheet or packaging for precise measurements. Material: sensor housing and sensing elements are built to withstand exhaust conditions; exact materials should be listed in the product datasheet. Performance: provides realtime oxygen readings to support stable engine operation, efficient combustion, and emissions control. Use cases Replacement to resolve check engine light or diagnostic codes related to a failing rear O2 sensor on a 2009 BMW 7 Series. Preparatory maintenance before emissions testing to ensure the rear sensor is functioning correctly. Routine maintenance replacement to prevent degraded sensor readings that can affect fuel trim, catalytic converter health, and overall drivability. Notes Please verify exact fitment for your vehicle by checking the OE part number, VIN, or crossreference guide. Professional installation is recommended to ensure proper installation and reliable electrical connection.