Exhaust Pressure Sensor Mazda 6/Cx5

22627-AA500 The DPF Sensor (or Diesel Particulate Filter Sensor) is an important element of your Mazda CX5 & Mazda 6 exhaust system which monitors the soot level emitted by your engine. They assist the ECU in deciding when to kick in the regeneration cycle to burn up soot particulates from the exhaust gas or if the DPF is blocked.