Diesel Particulate Filters (DPF)

DPF Cleaning and Servicing

If you are having issues with your DPF filter you may want to consider cleaning your DPF filter and other options, this is a service we offer – please let us know if we can help with this service as a dpf cleaner may be a much better solution for you and will keep your car legal come MOT time.

DPF Refitting and DPF Installation

In the past DPF removal has been very popular; some estimates are that there are as many as 30,000 diesel vehicles on the roads in the UK alone that have had their DPF system removed. But the public is now much more aware of the dangers and side effects of removing a DPF system from a vehicle. Laws and attitudes have changed in the past 3 years meaning many who have previously removed their DPF filters now wish (or need) to have them refitted.

OE Manufacturers’ DPF filters are very expensive, and the job to refit a DPF system can be very costly, But One Stop Electronics can help, we have access to high quality replacement DPF filters and have the ability to reactivate a vehicles DPF system, if your vehicle has had its filter removed in the past perhaps even by a previous owner without your knowledge – we are here to help, with DPF software and parts to refit your system and make your car road legal again – just ask for details.

Diesel Particulate Filters

Before you remove your DPF and delete it, or remove your DPF and send it way for cleaning; STOP Now! One Stop Electronics can help!

  • 98% success rate for blocked DPF units
  • No charge if we can’t clean your DPF unit
  • No Quibble DPF Regeneration Guarantee
  • Over 25 years experience in tuning and garage service
  • Mobile and Workshop facilities
  • Combine you DPF cleaning with performance or fuel economy tuning for a discount


Is DPF Removal illegal?
How will removing the DPF affect my MOT?
Will my car fail MOT if I remove the DPF?
What about emissions?

These are the sort of questions we are asked on a daily basis and therefore we have compiled some information on this page relating to current and expected MOT regulations to try and shed some light on this often mis-informed subject.


Diesel Particulate Filters image

Emissions Test
Petrol vehicles are subject to an emissions test, during this test the exhaust gasses and lambda readings are measured and recorded. Carbon Monoxide (CO), Hydrocarbons (HC) and Lambda (~).

Diesel vehicles are NOT subject to an emission test, instead they are subject to a simple Metered Smoke Test. During the diesel smoke test the opacity of the smoke is tested, the exhaust gasses are NOT measured or recorded.

How will removing a DPF affect the smoke test?
A DPF is designed to filter out soot from diesel exhaust gasses, therefore a DPF will reduce the opacity of the smoke.

So why does a car not fail the smoke test if the DPF is removed?
Removing the DPF will not cause the opacity level to rise high enough to fail, in fact, it is very difficult to get a diesel vehicle to fail an MOT smoke test, the fail mark is very high.
It is worth remembering that DPF’s were not designed to help cars pass the MOT smoke test, they are a result of recent European legislation and the continued pressure on car manufacturers to clean up their emissions. In fact the diesel smoke test was implemented before DPF’s were even applied to cars.

Is it impossible to fail the smoke test?
If a vehicle is in good mechanical condition and has been well maintained then removing the DPF will not result in a smoke test failure.  However, a mechanical engine issue which results in the engine running too rich and producing excessive smoke could lead to a failure.  In fact, it is quite common for a simple mechanical issue such as a split intercooler pipe or jammed EGR to cause the engine to produce excessive smoke and block the DPF, once the DPF is removed the underlying engine issue often becomes apparent.