the dpf problem & solutions


dpf Removal

There are probably hundreds of thousands of vehicles out there today with no DPF filters fitted because they have been removed.

This was and is due to the high replacement costs of a blocked or worn out DPF Filters.

the downside

The downside is the law, most people cannot afford a new DPF filter.  So they have no choice but to find an alternative solution to the problem. With the new MOT changes that took place on  the 20th May 2018 it has given the MOT inspector more powers to inspect the DPF filter fitted to your car.

The DPF Problem

This article we will discuss the problems with DPF filters and what we can do to rectify the problem as well as how to maintain your vehicles DPF Filter.

We hope you find this article helpful and of course if you have any question please get in contact.

There are lots of problems and checks that need to be addressed before a DPF can be removed. If you decide to have your DPF removed from your vehicle you must be aware of the follow MOT law.

Stricter rules for diesel car emissions

There are stricter limits for emissions from diesel cars with a diesel particulate filter (DPF). A DPF captures and stores exhaust soot to reduce emissions from diesel cars. Check your car’s handbook if you don’t know if your car has a DPFYour vehicle will get a major fault if the MOT tester: can see smoke of any colour coming from the exhaust finds evidence that the DPF has been tampered with.

Removal Procedure

Once you have made the conscious decision to remove the DPF you must follow the following set of rules:

  1. Do not remove the DPF until the ECU software that controls the DPF has been removed. This is because if you remove the DPF before the software solution has been added and the remapping company you use cannot apply the software solution or delete then you are stuck with a vehicle with no DPF and no solution to remove all the warnings and fault codes that will be generated. The vehicle will be underpowered and smoke heavily!
  2. You Must always conduct a full DPF regeneration be it static through diagnostics equipment or a forced regeneration where the car is put into regen mode but must be driven straight after the diagnostic session has ended before the DPF removal.
  3. Once your ECU remapper has visited the vehicle and has successfully deleted the DPF software (This will take around 1hr or less to complete depending on vehicle type).
  4. You can now instruct a garage to remove the DPF filter from the vehicle and remove the insides of the filter. Care must be taken when removing the inners as you don’t want to damage any sensors that are housed inside the DPF housing, as they still perform a diagnostic role on some cars. If any of the sensors get damaged then you will have to get the ECU remapper out again pay more money to remove the permanent fault codes generated from the damaged DPF sensors. If the sensors are worn, some vehicles will require a sensor replacement further added to the cost. Example: Temperature sensors, DPF pressure differential sensors and rubber piping.
  5.  Once the filter housing has been replaced back on to the vehicle you are good to go. It is always worth changing the engine oil as this will be contaminated with diesel.



Common Faults With DPF Filters

The most common faults are either:
  • Faulty Sensors
  • Fully blocked DPF because the car has not been able to conduct a full regeneration.
  • AdBlue or Eoyls tank is empty if fitted.
  • Pressure differential pipe work split.
  • The most missed diagnostic is that the DPF is just full of ASH!

Guide To Cost's

The costing list is as follows:
  • ECU Software Delete £250 this normally comes with a remap of your choice.
  • DPF Removal £300-£600 in total.
  • DPF Cleaning Using Ultra-sound & Bath £275-£350 depending on the size of DPF. (Ash Content Removal)
  • DPF Static Regeneration around £100-£150
  • Cgon Hydrogen Additive System purely preventative measure £459 all in.
  • Hydrogen Cleaning (Hydro Clean) of the DPF £100 – £150.
  • DPF Reversions this is if your vehicle has failed the latest MOT because the DPF has been removed. You will need the ECU Software re-instated and a new DPF placed back on the car typical cost £1,200 -£2,500.

DPF Ash Content Is To High

Most garages miss this problem as they wrongly assume that the filter is just full of soot. This is not the case the DPF will be full of ash particles. A DPF when it regenerates converts soot into ash, this is done by the DPF when it gets up to the right temperature to burn off the soot content. This then creates the ash and most of the time the ash stays inside the DPF and blocks it!

The Solution

The only Solution is to have the DPF removed and professionally cleaned. This will remove the ash content from the DPF and maybe give you another 15-25k miles of service. This procedure normally takes 2-3 days from start to finish but it really depends on how time efficient your garage is that supplies the service. The cost of this service can range depending on the vehicle type and DPF type. But it will be significantly cheaper than a DPF replacement.

Preventative Measures

There are a few preventative measures that can be taken to stop your vehicles DPF from becoming prematurely blocked they are as follows:

  • Drive the vehicle up and down the motorway and get the DPF into a natural state of regeneration at least once a week.
  • Try to use a high grade of fuel maybe 1 in every 3 tank fills.
  • Regularly conduct a Hydro Clean.

Get In Touch

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