We have the ability to regenerate DPF’s.
How do they work?
Diesel Particulate filters (DPF) catch bits of soot in the exhaust.
As with any filter they have to be emptied regularly to maintain performance. For a DPF this process is called ‘regeneration’ – the collected soot is burnt off at high temperature to leave only a tiny ash residue.
Regeneration is either passive or active
Passive regeneration
Passive regeneration takes place automatically on motorway or fast A-road runs when the exhaust temperature is high. Because many cars don’t get this sort of use vehicle manufacturers have had to design-in ‘active’ regeneration where the engine management computer (ECU) takes control of the process.
Active regeneration
When the soot loading in the filter reaches a set limit (about 45%) the vehicle’s ECU will initiate post combustion fuel injection to increase the exhaust temperature and trigger regeneration. If the journey is too short while the regeneration is in progress, it may not complete and the warning light will come on to show that the filter is partially blocked.