An exhaust gas treatment system includes a particulate filter to collect particulate matter from exhaust gas flowing therethrough. The particulate filter realizes a pressure thereacross in response to the exhaust gas flow. A delta pressure sensor determines a first pressure upstream from the particulate filter and a second pressure downstream from the particulate filter. A delta pressure module is in electrical communication with the delta pressure sensor. The delta pressure module determines a pressure differential value based on a difference between the first pressure and the second pressure and generates a diagnostic signal based on a plurality of the pressure differential values and a predetermined time period.