This engine air filter removes airborne particulate from the intake stream before it reaches the turbocharger and combustion chambers. It is the primary barrier between the operating environment and the internal engine components. A restriction in the filter element reduces airflow to the engine, causing a drop in power output and an increase in exhaust temperature. The filter element is designed to match the housing's seal geometry so that unfiltered air cannot bypass the media. When replacing the element, inspect the housing seal surface for debris and ensure the element is fully seated before closing the cover.