Experts are warning that removing a car’s diesel particulate filter (DPF) is not only illegal, it’s also a waste of money.
The message comes after a recent BBC investigation that found as many as one in 10 garages were offering the service, despite a removed DPF now being an MOT failure.
Many modern diesel cars are fitted with DPFs in the exhaust system to reduce soot emissions, however they can get clogged up when the car’s used mainly for short journeys.
Until recently, there was nothing stopping garages removing a clogged-up DPF rather than asking the customer to shell out a potential four-figure sum for a new one.
The car would run adequately without it, but emit more soot particles into the atmosphere.
As of February 2014, the annual MOT test includes inspection of the DPF. If a car was fitted with one when it was new, it must still be there.
However, garages are misleading customers by not telling them that removing the DPF could cause their car to fail its next MOT.
One company, DPF Clean Team, offers a service that cleans out particulate filters, working with police forces, car supermarkets and garages across the UK.
Director Cameron Bryce said: “Prior to a change in legislation, cars were MOT tested on emissions levels and not whether their DPF was attached. Garages have a responsibility to inform their customers of this change and those removing the filter in the hope of bypassing the system are not providing great customer service.
“What workshops, and potentially customers, are missing is the fact that it is far more expensive to remove and remap the DPF than cleaning the filter. It is important both sides understand the consequences and share this responsibility.”