DPF Removal - Diesel Particulate Filter and FAP Service

A DPF (Diesel Particulate Filter) also known as FAP on some French vehicles, is a device fitted to the exhaust system of modern diesel vehicles to reduce particulate emissions and meet European emission standards. It does this by trapping Soot (Particulate Matter - PM) from the exhaust gasses while letting the gasses flow through the system. As with any type of filter a Particulate Filter needs to be cleaned regularly to function properly. With DPF's this is done by a process known as Regeneration which involves a combination of a Catalyst function in the system and burning the soot to gas at a very high temperature leaving behind an Ash residue within the DPF.

• Problems with your DPF?

• warning lights on your dash?

• 'Limp home' safety mode?

• Poor acceleration and MPG?

• Facing expensive repair costs?

Are you confused what the best solution is for you and your car?

Regeneration should be an automatic process taking place in the normal use of your vehicle.

DPFs have been in common use in passenger cars and light commercials from around 2003 in preparation for Euro 4 regs (2005), with Peugeot, Renault and BMW being early takers. Euro 5 (2009) made it compulsory for diesel cars and light commercials to have a DPF fitted and Euro 6 2014 will tighten this up further.

PROBLEMS ENCOUNTERED WITH DPF

If regeneration doesn't function properly it leads to a build up of soot affecting performance and fuel economy, left unattended this will result in a Blocked DPF which can ultimately cause very expensive damage to other engine components. A blocked DPF is also potentially dangerous as it can cause overheating in the exhaust system and cause a fire risk. To prevent this damage most newer vehicles will go into 'Limp Home' safety mode at this stage, meaning the vehicle will have reduced power to protect itself. For regeneration to take place it requires the vehicle to be driven regularly at some speed on open roads e.g. motorway driving, typically driving at around 2500 RPM for approx 20mins.

However, for diesel vehicles used primarily on short stop start journeys e.g. local deliveries, taxi's etc, the vehicle does not get the chance to heat up sufficiently and is unable to carry out a full regeneration process.

Even if the regeneration functions as it should, over time the Ash Residue will build up in the DPF and have the same affect ultimately resulting in a blocked DPF. For this reason a DPF is classified as a Serviceable Item by the vehicle manufacturers like brake pads or air filters etc.

WHAT ARE MY OPTIONS?

By the time your DPF warning lights are visible your DPF will already be significantly blocked. Forced regeneration by a garage or a 'blast down the motorway' is often not enough to cure the problem, as at this stage it might be too late but can be worth trying. If a forced regeneration does not work realistically you have the following 3 options:-

• DPF Replacement - this can be very expensive as it is only advisable to use genuine parts are aftermarket DFP's tend to be inferior and don't last very long.
• DPF Cleaning Treatment - which can work but is often too little to late to rectify an old already damaged DPF.
• DPF Removal - We can remove the DPF system meaning you will not have any future DPF blockage problems. This is usually the most cost effective option (but you must consider the legal issues with removing as outlined below). We can remove the DPF unit, carry out the modifications to remove the blockage and refit the modified unit, recalibrate the ECU, reset the warning lights and run a road test. We can also add a performance-economy remap at the same time to improve fuel economy and performance. On completion there is virtually no visible change to the system. Our solution is reversible so you can refit a DPF again in future if you wish.

The ideal DPF solution for you depends on your circumstances e.g. type & condition of your vehicle, your usage, your future plans i.e. whether you intend to keep or sell the vehicle etc and your budget.

WHAT ELSE SHOULD I BE AWARE OF?

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, so PLEASE REMEMBER IF YOU HAVE DPF PROBLEMS THERE IS OFTEN AN UNLYING FAULT CAUSING THIS WHICH WILL NEED ADDRESSING.

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 or replace 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. We 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 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.