Fleet News

Drivers reminded about new MOT rules on DPFs

Drivers of diesel cars are being warned not to fall foul of changes to MOT law covering diesel particulate filters (DPFs), which took effect last month.

The guidance is intended to help them overcome stricter rules surrounding emissions tests,

Prior to a change in the legislation cars were only tested on emissions levels and not whether their DPF was attached.

Now any car that should have a DPF but is found to have it missing will instantly fail.

The new rules have left tens of thousands of motorists facing bills of around £1,000 this month - the single busiest the year for MOT testing - according to Halfords Autocentres.

Rory Carlin from Halfords Autocentres said: “Rather than explaining why these important filters become clogged and offering a simple solution that will prevent the issue in the majority of cases, some garages have been removing the DPF.

“This practice has always been illegal but some companies are continuing to advertise the service as though it is a legitimate long-term solution. This means thousands of owners are now facing the cost of a buying a replacement DPF and having it re-fitted.

“A preventative exhaust system cleaner like Cataclean costing as little as £20 can help stop the DPF getting blocked. However, even in cases where a clogged filter has caused a warning light to come on all is not lost - a DPF cleaning and regeneration product like PowerMax is likely to solve the problem in the majority of cases for around £30.”

DPFs often become clogged with soot if a vehicle is frequently used to make short journeys because it does not get hot enough to burn off the particulates that build up over time, unlike motorway journeys.

Fuel and exhaust system cleaner Cataclean not only helps all types of diesel and petrol cars pass their MOT emissions test by cleaning the vehicle’s engine but, providing it is used before the DPF has become clogged, can prevent the DPF failure by lowering soot emissions by up to 60% - with further treatments once a quarter keeping it clean.

William Jones from Cataclean Global Ltd said: “The changes to the MOT test relating to DPF removal were brought about by Department for Transport because of concerns that vehicles were being modified in a way that is was detrimental to people’s health. Effectively removing the DPF undoes the work car manufacturers have done to improve emissions standards.

“Our message to motorists with a DPF is to keep their engine clean by using Cataclean as a preventative measure before problems arise. For motorists, running cars not originally fitted with a DPF Cataclean can help a car pass its emissions test and help you save money by improving engine performance and making your car more fuel efficient.”

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  • rob - 13/03/2014 12:00

    Nice marketing job for cataclean The actual change to MOT rules is a visual inspection of the dpf only which means as long as the unit has been gutted rather than removed it will still pass an MOT the vast majority of people doing dpf removals are clued up on these changes and have been removing dpfs in a fashion which will allow cars to still pass an MOT

    • christopher.smith - 13/03/2014 13:50

      @rob - Halfords told us that "'gutting' a DPF (removing the internals that filter the vehicle's emissions) is illegal and should still result in an MOT failure. It is also worth noting that this practice will also increase emissions, potentially trigger dashboard warning lights and invalidate manufacturers' warranties." They added: "We are also aware that there are products on the market that have been devised to get around the rules - that look like a DPF but are hollow - and would urge drivers not to be tempted by the companies offering them for the above reasons."

    • Rob - 20/04/2014 14:06

      @Christopher Smith, Fleet News Web Producer - I would suggest you get your technical information from a better source whilst gutting a dpf certainly isn't allowed the mot tester is not allowed to assume it is gutted and must give the benefit of the doubt even if the dpf has obviously been tampered with ie visible cuts/welds scary that a company the size of halfords don't seem to understand the rules that their own MOT tester should be adhering to.

  • James - 13/03/2014 15:01

    Fleets and motorists don't just remove DPFs (and Catalytic Converters) because of failure / blockage. I've heard quite a few stories of them being removed to avoid theft; which is a growing problem in the UK and in Europe. In either case it is illegal and the units are designed to help reduce vehicle pollution which is definitely a good thing.

  • Martin McCloskey - 13/03/2014 15:08

    Have you tried Smog Doctor for cleaning out the DPF and CAT

  • Richard - 13/03/2014 16:38

    People only remove the DPF for one reason, they are doing the wrong type of driving. This isnt only the drivers fault but leasing/government/manufacturers fault. People are being forced to buy/lease diesels due to the tax benefits and not their true usage. Many companies have Diesel only fleets eve if you are doing 5k per year. Sadly, the retail user doesnt have much to select apart from diesel, diesel and more diesel cars. Petrol cars are going fast and for a premium and in some cases for more than a diesel. The industry should look at this and I hope businesses will review their fleet and start using petrol vehicles. DPF, flywheels, EGR's are just the start, soon you will have the adblue problems and additional costs. Dont buy diesel if you are doing low mileage and crutially dont be a sheeeep and follow the others in the office!

    • christopher.smith - 13/03/2014 16:39

      @Richard - It's certainly a valid discussion - we looked at the topic of diesel-only policies in depth in October last year, and you can find the article here. http://www.fleetnews.co.uk/fleet-management/insight-is-the-diesel-only-policy-dead-/48971/

  • Iain Corby - 20/04/2014 13:06

    what a load of rubish, if you remove the dpf get your car {ecu} remaped then the emissions are lower as the car runs more efficiently so what is the problem not only that but a lot of other components will last longer and everything will be a lot smoother.

  • kelvin - 27/05/2014 20:32

    I was very interested to read this article until it mentioned `a guy from Halfords `- tinky winky would have more knowledge on the matter.

  • The Equalizer - 26/10/2014 19:56

    Better still, give UK consumers the same level of protection that U.S consumers have had since 1996, in the form of a Federal Emissions Warranty (Google it). This is a 80k mile / 8 year warranty covering all major emissions reducing components, including Cat Converters and DPF's. This ensures that vehicle manufacturers use fit for purpose emission control components on vehicles or they have to pick up the full tab for repairs and replacements should they fail. If DPF's will not stand up to the same minimum level of warranty, then they shouldn't be fitted to cars, end of.

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