Where is the mass airflow sensor on a 2009 scion xb?

The mass airflow sensor (MAF) on a 2009 Scion xB is located in the intake air duct, between the air filter and the throttle body. It is typically housed in a rectangular or cylindrical plastic casing and can be identified by its electrical connector. To access it, you may need to remove the air intake assembly. Always ensure the engine is off and cool before attempting any maintenance.