Removing a Blocked Diesel Particulate Filter (DPF)
Removing Common Rail Diesel DPFs can be a labour intensive job as some particulate filters are part of the catalyst and therefore part of the exhaust manifold or front pipe assembly. These are often fitted as close to the engine as possible to help maintain a high temperature and to assist fast warm up. V6 and V8 engined vehicles may have two DPFs and are often even more difficult to work on due to obstructions like steering racks, sub frames and turbochargers etc., restricting access to exhaust manifold nuts or bolts. Older vehicles can present even more problems due to corrosion or seizure, in some extreme cases making it necessary for the garage to use oxy-acetylene burning equipment to remove the DPF.
DPF Core Removal – Before
DPF Core Removal – After
After removing the DPF it will be necessary to either fabricate or purchase a replacement by-pass pipe ensuring that any exhaust pressure and temperature sensor take-off points are retained.
Eyeing-up the job – Refitting
Where possible, CRD Performance will remove the DPF assembly, empty its contents and seam weld it back together so that it still appears fully intact.
With the DPF now removed the engine management system still monitors its DPF pressure and temperature sensors to check they are present and working.
Without this, the ECU will detect an error, switch on the engine management light and enter ‘limp’ mode, rendering the vehicle almost undriveable.
Software Upgrade (aka DPF Deletion)
If the Diesel Particulate Filter is physically removed from the exhaust system and the ECU not remapped to accept the changes, then sooner or later the engine management system will go into ‘limp’ mode, or LOS (Limited Operating Strategy). When in limp mode the vehicle may have restricted power and, if fitted with an automatic transmission, it may even lock into top gear to limit acceleration.
While monitoring ‘pre’, and on some vehicles ‘post’, DPF differential pressures, the vehicles’ management system monitors the current state of the DPFs and detects if one or more are present. Software DPF removal involves reprogramming the vehicle’s ECU to ignore any abnormally high or low readings from either the pre or post DPF differential pressure sensors. As previously mentioned, it is still necessary for all DPF pressure sensors to be present and working. Software changes can only be made to open up pressure monitoring parameters, preventing regeneration, not to ignore the sensors altogether.
Software Power Upgrades
Some customers, while having their ECUs re-programmed to delete the DPF, take the opportunity to have their engine re-mapped for additional power, better driveability and better fuel economy. CRD Performance use several engine remapping companies for this purpose, who offer a discount if both programmes are carried out at the same time at our workshop in Bolton.
DPF Emulators
On some vehicles, software DPF deletion is not possible; this is especially true for some Japanese and Asian vehicles. CRD Performance now have available a full range of emulators which are programmed specifically for each vehicle make and model. Installing these does not involve interfering with the vehicle’s ECU since the emulator is instead wired into several of the engine sensors. These units work by fooling the cars ECU into believing that the DPF is still present and maintained in a clean condition, therefore not requiring any regenerating, even though it has in fact been removed.
Beware of cheap DPF Removals
We frequently have vehicles brought to us in Bolton to correct a previous attempt to remove a DPF that has gone horribly wrong. Often the vehicles are in an undriveable condition, stuck in ‘limp’ mode, with the engine management light on, yet no fault codes present.
Be very aware of cheap quotes – you have been warned! “Cheap today, dear tomorrow”.
CRD Performance is the North West’s leading DPF removal specialist, providing DPF removal services for all Lancashire and Greater Manchester districts, including Manchester, Liverpool, Warrington, Blackpool, Bolton, Stockport, Preston, Blackburn, Oldham, St Helens, Chester, Rochdale, Southport, Birkenhead, Wigan, Burnley, Salford, Crewe, Wythenshawe, Ellesmere Port, Runcorn, Bury, Bootle, Wallasey, Huyton, Widnes, Sale, Macclesfield, Lancaster, Middleton, Stretford, Ashton-under-Lyne, Leigh, Swinton, Urmston, Walkden, Altrincham, Leyland, Skelmersdale, Eccles, Accrington, Darwen, Denton, Radcliffe, Tyldesley, Chorley, Chadderton, Prestwich, Hyde, Wilmslow, Winsford, Reddish, Northwich, Nelson, Ashton-in-Makerfield, Heywood, Fleetwood, Kendal, Whitehaven, Farnworth, South Turton, Workington, Formby, Saddleworth, Marple, Hindley, Ormskirk, Whitefield, Droylsden, Golborne, Westhoughton, Congleton, Stalybridge, Clitheroe, Rawtenstall, Penwortham, Royton, Failsworth, Colne, Little Lever, Little Hulton, Great Lever, Kearsley, Horwich and Worsley.
Evolution Chips – Authorised Dealer
CRD Performance Bolton are privileged dealers for Evolution Chips and are fully equipped with the latest New Genius serial OBD Dealer handset and new BDM Trasdata ECU reading and writing interface.
Evolution Chips are without doubt one of the leaders (if not the leaders) in petrol and diesel engine remapping; don’t take our word for it, just ‘Google’ them. Not only do they offer performance remapping for all types of engines including direct injection petrol GDI and FSI but for diesel DPF and EGR removal also.
Evolution Chips remaps are expertly developed and optimised individually for each vehicle. As an Evolution Chips dealer, we are provided with these maps, in the form of a data file, which we use to reprogram the vehicle’s ECU, usually in one of two ways; Genius or Trasdata.
One of our Geniuses at work
Evolution via Genius
The car’s engine control unit (ECU) can sometimes be programmed through the on board diagnostic (OBD) socket which is usually located near to the driver’s seat. For this we use the Genius.
The Genius is a hand-held, stand-alone unit that allows the remap to be transferred to the vehicle’s ECU via the OBD socket without the need to remove the ECU or gain access to it.
Evolution via Trasdata
Trasdata System
On some vehicles it is necessary to remove the ECU and to programme it on the bench using Trasdata. This is a very expensive piece of kit that most dealers haven’t invested in. The Trasdata interface reads and writes data directly off of the main processor rather than through the OBD. This method is often referred to as BDM – Back Door Mode.
While looking for a software re-mapping and DPF deletion company to partner with, CRD Performance spoke to and checked out many who claimed to be either the best or even cheapest. We soon decided to contact Evolution Chips and after lengthy technical discussions with both the owners, Kenny and Stuart, realised that they clearly know what they’re doing and were from a motorsport background.
Scan Tool
Scan Tool
When customers bring a vehicle to us for re-mapping we normally carry out a road test and fault code read using a scan tool, any relevant concerns will be brought to the customer’s attention. The original file is then read and E-mailed to Evolution Chips who then use some of the vehicles identity and security data to create a modified file from their vehicle database and return it to us. The modified file is then installed and the vehicle road tested, a copy of the original file is retained by us and for additional security a copy held in the archives at Evolution Chips.
DPF Removal & Deletion
As diesel specialists, we frequently have vehicles brought to us for DPF rectification that are still within their manufacturer’s warranty period, often because the Main Dealer has refused to rectify the fault under warranty, blaming the owner’s driving style or vehicle usage. As well as fixing many DPF problems we are often asked to remove the diesel particulate filter completely from the exhaust system and to carry out any re-programming of the vehicles computer that this procedure requires.
 DPF Core Removal |
 DPF Core Removal |
More DPF removal information and a price guide can found in our DPF section:
Click here to go to the DPF section
To find out if your vehicle can be Evolution Chipped click on the link below.
Evolution Chips – Vehicle Search & Prices
Recommended Reading:
The hidden dangers of diesel tuning and remapping:
A few things to consider before purchasing a remap.
The cheap remapping file fitters normally install files with no immobiliser software and no factory bug fixes so at best you get a car with more power and a lot of bugs, or at worst one with an immobilised ECU that nobody can access or even one that does run but a thief can take from you in under 10 seconds. (We are not suggesting they tell thieves the address and registration of the car’s this was done to of course…)