Isuzu's DPD (Diesel Particulate Diffuser) was introduced in 2017 on their 4JJ1 engines for their D-Max and MU-X vehicles. The DPD system which is made up of a DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter), traps PM (Particulate Matter - soot) from the diesel engine's exhaust. The DPD was introduced (together with some other engine improvements) such that the engine will be compliant with the ever tightening Euro-5 emissions. The DPD system traps PM and eventually will become full. Therefore, the DPD system will complete a 'burn-off' or regeneration in order to burn off all the trapped PM. This occurs approximately every 500km's in the D-Max and MU-X vehicles. This video will show you an active regeneration taking place during normal driving conditions.
