METHODS AND SYSTEMS FOR INTAKE AIR FILTER DIAGNOSTICS

Methods and systems are provided for diagnostics of an intake air filter during vehicle-off conditions. In one example, the engine may be reverse rotated, unfueled, and air flow via the exhaust manifold and the intake manifold are estimated and compared to a baseline air flow. A blocked intake air flow may be indicated based on the comparison between air flow via the exhaust manifold and the intake manifold and the baseline air flow upon opening a secondary flow path to atmosphere.