A Diesel Particulate Filter (DPF or FAP for short) is a filter found in the downpipe section of the exhaust and is specifically designed to reduce the amount of Diesel Particulate Matter (Soot/Ash) passing through.
A Diesel Particulate Filter (DPF or FAP for short) is a filter found in the downpipe section of the exhaust and is specifically designed to reduce the amount of Diesel Particulate Matter (Soot/Ash) passing through. The objective of this filter is to create cleaner / more eco friendly exhaust gases being released into the atmosphere.
A diesel particulate filter will gradually become restricted and more clogged up as a normal part of it’s service life. A process called regeneration is designed to occasionally ‘clear out’ the particulate filter. Unfortunately this needs specific driving conditions and when these are not met, the degree to which the filter is blocked can surpass the engine managements ability to regenerate the filter – leading to problems with power loss (see detailed list below) and even in the absolute worst case, risk to the car due to overheating of the filter.
The images below show different examples of the a DPF, as you can imagine with the first image this is very restrictive and easy to block causing fault codes and running problems on the car. Standard DPF Filter Removal
A blocked DPF can cause many problems including loss of power, economy and throttle response. With more extreme cases, filters that are extremely blocked can cause the engine not to start at all.
Generally speaking a blocked DPF is usually caused by another underlying issue. It is worth undertaking further diagnostics to find the route cause of the blockage.
Things what could lead to a blocked DPF:
There are multiple faults codes and symptoms that can point towards a faulty / blocked DPF.
Symptoms:
Warning Lights:
There are 4 main solutions when you experience a blocked DPF. It is also worth diagnosing the vehicle as a lot of the time a blocked DPF can be caused by another issue. (Check DPF Sensors, EGR Valve and Swirl Flaps).
The first solution is to try a forced regeneration. This is for cars that have only just started to show symptoms that the DPF is blocking. If this fails to work the DPF may be too far gone for this process.
Pro’s
– If the forced regeneration process is successful this is the cheapest way to cure a blocked DPF.
Con’s
– A forced regeneration cannot always be preformed, depending on how blocked the DPF is.
The second solution would be to clean the DPF using latest advanced carbon cleaning technology break down carbon and soot deposits.
Pro’s
– The price of this is a fraction of a replacement unit.
– The vehicle may respond well and get 1,000 of more miles with any issues. .
Con’s
– After testing a cleaned DPF it made no difference in power, compared to a blocked DPF (150k Miles).
– In term of tuning, a DPF filter (cleaned or blocked) is a massive restriction to Air Flow and EGT’s (Exhaust Gas Temperatures) resulting in lower power figures.
The third solution would be to replace the DPF. Generally speaking, these can be very expensive from the dealers, some costing upwards of £1500 + VAT.
Pro’s
– The vehicle will remain as it came from the factory meaning it will stay within the manufactures warranty.
Con’s
– A new unit plus the labour is an expensive job to undertake.
– In terms of tuning, a DPF filter (new or blocked) is a massive restriction to Air Flow and EGT’s resulting in lower power figures.
The forth solution is to remove the DPF all together eliminating the problem with no risk of the same problems occurring in the future.
We must advise that in the UK this is illegal and it’s the customers responsibility to ensure they comply with rules and laws relating to their home country)
Pro’s
– A DPF Delete including software is usually around half the price of a new replacement unit.
– Eliminates all chances of the DPF blocking again in the future and further expenses.
– Removing the filter element will increase air flow and lower EGT’s resulting in better performance and economy.
Con’s
-If removal of DPF is detected it may affect manufactures warranty and MOT .
There are a range of DPF Delete options in the market,. For certain makes and models a complete Stainless Steel Downpipe which completely removes the DPF section of the exhaust and fits directly in place of the standard downpipe. For the models we don’t have off the shelf downpipes then custom exhausts can be made.
Another option is to cut out the filter from the DPF housing itself, still removing the problem but visually leaving the DPF Housing in its original place for visual inspections. This method can also be carried out at home if you have the correct tools and equipment available.
Once removed custom Tuning can reprogram the ECU to remove the software faults stored on the cars memory and reprame the new sensore parameters .
Once removed custom Tuning can reprogram the ECU to remove the software faults stored on the cars memory and reprame the new sensore parameters .
After deleting the DPF you are also able to delete the EGR Valve, this valve is used to lower the emissions of the car but are often prone for failing. The valve works by recirculating some of the exhaust gases back into the engine through the air intake system, reducing the amount of emissions that exit the car.
The problem lies with the exhaust fumes that contain carbon deposits, these fumes are constantly being recirculated through the engine which over time will cause a build-up of the carbon deposits in the intake manifold and other in other parts including the EGR valve. This build up in the valve is often what causes them to fail.
There are two ways of removing the EGR System from the vehicle. The first way is by installing an EGR Delete Race Pipe Kit which we can supply on request depending on model.
Some cars may have a different EGR Valves or ones that are built into the inlet manifold. If this is the case you can still remove the EGR using blanking plates.
Once the valve is either removed or blanked off the vehicles ECU will no longer get a signal from the EGR Valve causing the emissions workshop light to appear on the dash board. Custom Tuning can reprogram the ECU to remove the software faults stored on the cars memory.
No, in fact having a DPF will cause more problems than removing it altogether. Once the DPF is removed there is no need to worry about regeneration, power loss or expensive bills from the dealers.
A blocked DPF will use more fuel than usual as it is making the engine work a lot harder, removing the DPF will help the exhaust gases flow freely which in most cases will see an increase in MPG.
In the UK it is illegal to remove any of the original emissions equipment fitted to a vehicle from the factory. Vehicles with the DPF removed and detected will fail an MOT.
It is the customers responsibility to ensure they comply with rules and laws relating to their home country. Custom Tuning accepts no responsibility for the use of this part on the public highway where removal of emission controls is prohibited.
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Why Don’t Manufactures Send Cars Out At Their Best?
We get asked this quite often, the reason is that they like to sell you the SRi, GTi or XSi model. This is usually the same engine with a different map on the ECU.
PLEASE NOTE that all services we provide are subject to our terms and conditions, which can be found on our website at [URL] or provided by us on request. If you require a copy of our terms or conditions please contact us at [contact@custom-tuning.co.uk] and we will be happy to provide these to you, these can also be found on our website.
Certain vehicle modifications may render your vehicle illegal for use on roads in the United Kingdom or elsewhere. If you intend to purchase modifications or tuning services from us, you must ensure you are aware of the laws surrounding the use of modified vehicles in the United Kingdom or any jurisdiction where you intend to use the vehicle.
Any modifications made to a vehicle or tuning performed on a vehicle’s Electronic Control Unit (“ECU”) may invalidate (i) the insurance policy for the vehicle or (ii) the terms of a hire purchase contract or personal contract purchase which applies to the vehicle or (iii) the manufacturer’s warranty for the vehicle All customers are responsible for ensuring they seek the appropriate approvals from any third parties required to undertake any modifications or ECU tuning.
We are NOT responsible or liable to you for your failure to do so.
Factory-installed Diesel Particulate Filters (“DPF”) and Exhaust Gas Recirculation (“EGR”) systems are designed to limit harmful vehicle emissions. When these systems get blocked or obstructed they can reduce the airflow to your vehicle, causing reduced engine function or in some cases engine failure. If you request that we remove these systems (including any associated ECU reprogramming) then by doing so you acknowledge that removal of DPF or EGR systems is illegal for vehicles on roads and public highways in the United Kingdom. A vehicle without a DPF or an EGR system will fail its MOT and you may incur legal consequences for using a vehicle on the road without these parts fitted, including fines, points on your driver’s licence or potentially jail time.
Removal of certain functions and features of a vehicle, including but not limited to DPF, EGR, lambda sensors, catalytic converters, AdBlue and vehicle fault codes are subject to local laws and regulations. We advise that all customers ensure they are aware with laws and regulations applicable to on-road vehicles in the UK before requesting any systems removal work.
