DPF Now Included In MOT

Published Date: 7th Feb 2014

Tests for diesel powered vehicles are to be tightened to ensure vehicles have a diesel exhaust filter if one had originally been fitted to the car as standard, the Roads Minister Robert Goodwill has announced.
Testing stations and garages are now required to check the diesel particulate filter (DPF) in the inspection of the exhaust system as part of the MOT test (or the yearly test for heavy vehicles) from February 2014.

The vehicle will fail the MOT test if the filter had been fitted as standard but is found to be no longer present.
The filter works by trapping solid particulate matter from exhaust gases. This type of filter has been used for more than 20 years and meets European emission standards, improving air quality and health standards.

Some firms offer services to remove the filter, claiming it will improve the economy. But it is an offence to drive a vehicle that has been modified this way, as it will no longer meet the emissions standards the car achieved when it was approved for sale in the UK.

Roads Minister Robert Goodwill Explained:

I am very concerned that vehicles are being modified in a way that is clearly detrimental to people’s health and undoes the hard work car manufacturers have taken to improve emissions standards. It has become apparent the government had to intervene to clarify the position on particulate filter removal given the unacceptable negative impact on air quality.

This change to the MOT tests makes it clear – if you have this filter taken off your car it will fail the test.
The filters need to be ‘regenerated’ regularly through burning the soot to gas at a very high temperature, leaving behind a residue. If not carried out properly, regeneration can lead to a gradual build-up of soot, which can possibly affect performance. This has led to some diesel vehicle owners opting to remove the filter, which makes their car illegal for road use.