2006 BMW x5 reported 95 reliability failures, air quality relative to engine throttle.

Cause: The air filter element is dirty or damaged, or improperly installed, which reduces the recent quantity, or the air mass flowmeter is damaged, and the air quality cannot be accurately measured. There is carbon deposit in the throttle, and the throttle opening increases the actual intake air volume due to carbon deposit, but decreases due to carbon deposit blockage.