It is often said that you should go for a blast down the motorway to clear the DPF. Please note this is only partially true. If the DPF is blocked beyond the capacity for regeneration or blocked due to Ash residue, you will do more harm to your engine.
There are many DPF cleaning additives available promising a magic cure for DPF. We have yet to find one that will clear a blocked filter and will certainly not clear an Ash blocked filter. Some products can however be useful in keeping a functional DPF in good health.
DPF units are closely linked with other emissions components, if these parts do not function properly they can help to block the DPF, similarly a blocked DPF can damage these components due to excess back pressure.
DPF units are located close to the Turbo, if the turbo is leaking oil it can help to block the DPF, similarly a blocked DPF can damage the turbo due to excess back pressure.
Some PSA engines fitted to Peugeot, Renault, Ford, Volvo and Nissan have an on board Fuel Additive System connected to the DPF to help regeneration. It is important to maintain this system and keep it topped up with the additive (only available from main dealers approx £130 per tank) if not it will block the DPF. In our experience this is often neglected, even by main dealers due to the cost. If you have the DPF removed this function as it is no longer required and can be disabled.
Some vehicles have a dedicated DPF or Emissions or Anti-Pollution warning light which is great, however many will just have an Engine light on. It is important to check by diagnostics why the light is on and not advisable to simply get the light turned off without investigation.
DPF work is complex and should only be carried out by experienced professionals with the correct specialist equipment. All work on a DPF has to be completed with the appropriate recalibration or reset on the vehicle ECU. It is not possible to simply delete the DPF electronically or just remove the DPF unit without work on the ECU.
It is our experience that many garages including main dealers are not knowledgeable in DPF and related issues. Our dealers often see customers after they have spent a lot of money on the wrong fixes as the DPF fault was not correctly diagnosed.
Diesel Particulate Filters were designed with good intent to reduce particulate emissions and offer a better environment. In theory a DPF would trap soot in urban areas and then regenerate on the open road, unfortunately this does not always work well leading to expensive repairs.
The fact that DPF units are made with expensive minerals like Platinum, that excess fuel is needed for the regeneration process and that ultimately the accumulated soot and ash has to go somewhere back into the environment which many now question the overall environmental value of the entire life cycle.