What is the DPF?

Emissions requirements for new vehicles require Particulate Filters to be fitted to the exhaust of diesel vehicles since the ‘Euro 5’ standards were enforced in 2009. Prior to this many vehicles also have a DPF fitted in anticipation of the change to regulations. This ‘Euro 5’ and beyond standards aim to deliver reductions of >80% in soot (diesel particulates). However, these filtration systems are not without problems causing DPF warning lights, engine limp mode safety activation, reduced efficiency/mpg and poor engine performance.

The diesel particulate filter is mounted as part of the exhaust system. For the filter to operate correctly, it must regularly run a regeneration process to burn off the continuously accumulating soot. This process is completed by precisely regulating an increased temperature of the exhaust gas passing through the filter which then burns away the carbon deposits. To do so a sensor transmits data to an engine control unit that then calculates the precise requirement for post-injection fuel to increase the temperature during the regeneration phase. As with any filter, the DPF must be regularly emptied otherwise, over a period, it will start to clog up and will eventually become partially blocked. Passive regeneration of the DPF can only occur at fast speeds on a motorway or A-road so with all the local driving and short journeys for many vehicles this process cannot occur often enough eventually leading to clogging of the DPF.

Passive regeneration:

The DPF system is designed in such a way that when the engine is consistently running at approximately 2,500 rpms or more (e.g. on a motorway or fast A-road) the exhaust gas temperatures exceed 350°C soot particles are constantly being burned off without any engine management intervention.

Active regeneration:

Where the vehicle is predominantly used for urban mileage the exhaust gas temperatures fail to get hot enough passive regeneration is no longer achieved. Therefore, soot particles are no longer being burned off so start to accumulate inside the filter. This leads to clogging of the filter and when a threshold is reached the engine’s control unit (ECU) triggers the active regeneration at its next opportunity. You will need to then get a DPF clean, or a brand new DPF as your vehicle will go into limp mode. Over time this becomes extremely costly.

We offer DPF software delete, please note in order to delete the software we will need to physically remove your DPF.


  • Improved Performance
  • Increase Fuel Economy
  • Less Backpressure on engine
  • Better Throttle Response
  • Eradicate DPF Problems
  • Discreet
  • Long Term Savings