A sensor for sensing a differential pressure across an air filter in a motor vehicle. The sensor includes a sensor body having a first air passageway communicating with an atmosphere and a second air passageway communicating with an interior cavity of a manifold of a combustion engine. The sensor further includes a differential pressure sensor disposed within the sensor body and a microcontroller. The differential pressure sensor is coupled to the first air passageway and to the second air passageway. The differential pressure sensor is configured to measure a differential pressure between the atmosphere communicated to the differential pressure sensor via the first air passageway and the interior cavity of the manifold communicated to the differential pressure sensor via the second air passageway. The microcontroller is configured to receive the measured differential pressure from the differential pressure sensor. The microcontroller outputs an indication of how dirty the air filter is.
