posted 2 years ago

New MOT Rules Punish Diesel Particulate Filter Removers

Motorists Risk MOT Failure By Removing Filters

New rules mean that any vehicle missing its diesel particulate filter will - from February 2014 – fail the MOT test. The purpose of the device is to filter the residual particulate matter caused by incomplete combustion of the fuel, matter which would normally then escape into the air through the exhaust. This material incorporates carbon, organic chemicals, sulphate, nitrates, ammonium, sodium chloride and mineral dust which pollute the environment.

So, why remove a filter? Some drivers remove them to increase engine performance, although this usually requires remapping of the ECU, the computer that controls your car and its engine. Modern DPF filters also have to ‘regenerate’ when the filter is close to being full This involves heating any trapped material to an extremely high temperature so that it becomes gas. This heating process makes the engine use more fuel than normal, encouraging some drivers to simply take out the filter to solve this issue.

Removing this part makes a vehicle less environmentally friendly which the government rightly considers unacceptable. MOT testers must soon ensure that the filter is present on any vehicle equipped with one when new. If missing, he/she will issue a fail certificate

Minister Discusses Diesel Particulate Filter

Roads Minister, Robert Goodwill, revealed: “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 removed from your car it will fail the test”.

Dangers Of Air Pollution

The Government has claimed that air pollution causes twenty-nine thousand deaths per-year, and costs the health service about fifteen billion pounds. Particulate matter plays its part in these statistics. Furthermore, its effects are considered “more significant” than those from other air  pollutants. As such, chronic exposure can increase the risk of cardiovascular disease/lung cancer. Evidence suggests that there is no safe limit for exposure to fine particulate matter. There are wider environmental impacts too. Why? Because particulate matter incorporates nitrates, sulphates and ammonium that drive acidification (conversion of a substance to acid) and eutrophication (excessive richness of nutrients in a lake or other body of water). Both can damage natural ecosystems which can cause habitat loss and affect biodiversity. Particulate matter also contains black carbon that contributes to global warming. Best leave your filter on, then. 


My c4 picasso 1.6 hdi is a 2008 model it has a DPF however some of the same models in 2008 did not have a dpf strangely the dpf ones pay higher road tax as the co2 emissions are higher? £175 . My old 2.0 hdi picasso was only £140? A blocked dpf contaminates the oil with soot and causes turbo failure and engine blockages this causes even worse smoking . Why produce the same model with and without? If so why cant I take mine off?

My business is automotive electronics, ECU Remapping is one of my major business. I have been involved in DPF removal services now for 12 months and have become involved simply because of the amount of vehicle's that are suffering problems because of DPF's. Most people who drive these vehicle's are not aware even what a DPF is, let alone how to maintain one through regeneration. The result is that fail a lot and people cannot afford £500-£2000 for a replacement unit, especially when their driving habits are likley to have it fail again within a couple of years. The MOT station will only personal a visible check which in most cases in impossible. The car manufacturers/government need to come up with a better solution or DPF removal will continue.

"Sound engineering is that which gets the job done with the least complexity" to steal a quote... Complexity or sophistication of design is only required to compensate for or to overcome faulty design and substandard materials. The fact that cars have become very complex means not only are they based on unsound engineering but they are also crap at doing what they are designed to do. The last half a century of development has made them only slightly less crappy at performing the function of turning fossil fuels into work. Whatever designers do the petrol engine will continue to waste around three-quarters of the fuel poured into the tank and diesels will always waste about six of every ten litres of fuel they drink. These efficiencies are inherent in the technology and cannot be improved upon significantly. All the last half century has done is to reduce the amount of unburned fuel and partially burned fuel expelled from the chimneys of our vehicles because older technology tended to deliver far more fuel than was needed. That large quantities of unburned carbon is still being produced by diesels mean there is still a long way to go; there is a great big hole in engine design and all a DPF does is stick an Elastoplast over it. The government cannot and should not make a moral crusade out of something they have a vested interest in as it proves them to be shallow liars. The only moral and sensible way forward is to use the technology we have as efficiently as possible but that cannot be done without vast amounts of social engineering and losses of tax revenue. The situation is bad enough without the interference of hypocritical governments. At least it shouldn't be too long before Parliament is under water...

I once owned a Renault with a DPF filter and after having to give the car a god run to clean it out and after a while having to replace it at a huge cost have now gone back to the more conventional petrol engine. I think the new rules are good in some points but bad in others and he car manufacturers will no doubt be jumping with joy. Personly unless you do many long journeys on the motorway I would stay clear of the old oil burners and o back to petrol and yep you get less miles to the gallon but in the long run you save many thousands of pounds as you don't have a PDF filter to replace.

I'm examining the whole point of the DPF in the first place. This is a device, which, upon the illumination of a warning light on the dash, advises the driver to make a completely pointless drive down a motorway for no other purposes than for the pollution control on the exhaust to service itself. What sort of Green device encourages drivers to make long, needless drives at motorway speeds purely to maintain itself?. In a world where we are constantly reminded that fuel is in short supply, and that we need to limit the use of vehicles, very soon hundreds of thousands of diesel owners will be clocking up millions of additional miles between them every year, for no other purpose than because a dashboard warning light told them to do it. So the DPF reduces pollution, but at the expense of more fuel use, in order to carry out pointless motorways drives which wouldn't normally have been made. Because of the problems with DPF's most of which have been covered on Watchdog and also are evident on the AA website, many diesel owners are keeping their older vehicles for longer, or opting to buy older non DPF vehicles in order to avoid the potential £1000+ pitfalls, good advice it seems.

Your article is badly misinformed, most DPFs are removed because of VERY high replacement costs for prematurely failed or blocked units. (mechanic)

Its seems just the usual crap that the goverment are coming out with. Next they will all want us to revert back to riding horse back then charge you everytime it shites on the street. Before we know it we will have hoses stuck up our arses and charge for the almount of pollution we are putting out. People are struggling with bills etc and might run a banger which would fail the test and depend on there car so rip off britain absolute joke

What you have heard is wrong. In most German cities pre euro5 diesels (i.e those without a DPF) are not allowed in. They take air pollution a lot more seriously than us. Here in good old blighty your average diesel can be absolutely filthy and yet still fly through the MOT :-(

why did we only start to fit these after we went to low sulphur diesel.and why do they all go wrong. unless onece a week you get onto a motorway and drive at 80 miles an hour for 20 mins the exhaust doesnt get hot enough to ignite the particulate filter. and i have heard they are not compulsory in europe!!

They can not fail you for something that never was. You can't just fit a DPF without major modifications so if it was never fitted your ok.

Hmm - what if your vehicle never had a DPF in the first place, only a CAT - have we got to go out an buy one?

A lot of people on here are mixing up a catalytic converter with a DPF, you can't just take one out and put it back in for the MOT and you can't just empty out the inside like a cat and refit it either. I had a Vauxhall Meriva diesel and a replacement DPF was £1650 + vat OE.

I recently sold my diesel Range Rover because I had so much trouble with the DPF even after a manufacturers mod and a £5000 warranty claim. Went back to petrol, so no DPF! They are a good thing but need to work better to be successful.

I like many millions of drivers never knew about this, what you have now done is let unscrupulous people know how to save some money on fuel.

As one commented rightly it uses more fuel to burn off the filter particles and therefore is more environmentally bad but more so extra tax through fuel duty to the government .it's all about money not health surely vegetable oil is more environmentally friendly and it does smell nice especially with a little vinegar .

If you don't like DPF and EGR components then don't bloody drive a diesel! These components are there for a reason: to protect people from some of the toxic filth which diesels are synonomus with. Diesel PM10 and PM2.5 has now been proved to be a major cause of cancer and the oxides of nitrogen cause all sorts of respiratory health problems. Some of the commentators seriously need to educate themselves; its got nothing to do with global warming its people here in our towns and cities who have to suffer the effects.

The particulate filters fitted to diesel vehicles would seem to be somewhat delicate. My dealer recommended ensuring that a lengthy run on a motorway at around 70mph warmed the unit up sufficiently to burn-off any particulate deposits. This is on a Jaguar XJ6 TDVi model. The alternative is that a new filter has to be installed on the vehicle and these are not cheap. Removing one permanently clearly will not do from next February, as your diesel vehicle will fail the MOT, if you have. Diesel cars are best driven for lengthy journeys and not used just for local shopping-only type trips.

I know an easy way round it. Buy a second hand rover DIESEL (L Series engine) get over 60mpg on the motorway on the 620GSDI, (I had 2 of them) cheap to service (no dpf) and run on brand new veg oil (SVO) from the supermarket 79p a litre from bookers NO VAT either. The government screw us at the pump so I decided not to use the pump. Used to do a run from south london to burnley and would only cost me £20 return trip in fuel. And it made the road smell of a chippy. Lovely.

I don't drive a diesel (although have in the past)and I'm appalled at how many are willing to damage the health of our children by removing these filters to save a small amount of money. As a chemist, I can tell you, these particulates are incredibly toxic. Would you do this with asbestos? Where you do have cause for complaint is that these particulates are not formed by the diesel engine, they are waste material put in the diesel by the petrol companies as a cheap way to get rid of it. if they used the pure fuel they originally produce when they crack the petroleum, there would be no need for diesel filters!

My van (NV200) has a DPF filter fitted & I achieve 10 miles per gallon less than my brothers van (NV200) which has no filter. It wouldn't be so bad if I received the discounted road tax because of my emissions but as it is a van it still costs me £220 so why should I bother about the environment it would benefit me more to remove the filter. THINK AGAIN !!!!

I de-cat after mot and fit it back on for next one simples

Just another Government scam to make money from the motorist. It's ok for government to increase the dirt large energy companies can release but the odd little puff from a car exhaust will now be banned. Diesel cars are much more fuel efficient but we get penalised for trying

Just another way of getting MORE money out of the motorists, There's gonna be a lot of illegal cars out there.

If an mot tester can't see it he can't fail it. They are not allowed to remove items to looks either. Do these people consider that all those cars with those nice fancy full length plastic under trays cannot be properly checked legally....? Anyway back to dirty diesels. I have a landrover with a nearly straight through on it. It runs clean and passes emissions easily. It's 20 years old. If my truck can do it why can't new cars? And back to my 1st point. If you can't see it you can't fail it. An easy dpf fix is to remove knock the centre out and re-fit. Simple cheap easy and motable :)

I have a Suzuki SX4 with a Peugeot 1.6 diesel engine, at its last MOT I asked if it had a DPF and the tester didn't even know. So god help us if they bring in this law.

Having worked abroad In 3rd world countries I find it a bit rediculous vehicle emissions are such an issue in the uk/europe. As most 3rd world countries are still running ladas as taxis with no emission controls and a complete disregard to the environment. Do you honestly think the dpf system does enough to reduce to carbon footprint on the planet?

Just to make people aware of the depth of the issues, the automtic regeneration process failed repeatedly and caused contamination of my engine oil reslting in turbo failure. Alo know someone who lost their crankshaft because of diesel contamination of oil during flawed regen eewuence. Beware.

Surely when the DPF "regenerates" it pushes all the collected crap out of the exhaust, even if the driver does not floor the throttle - this is when you see a diesel car suddenly spew out a thick black cloud - so the nasty particulates end up in the atmosphere anyway! It's just a con to get through the emissions test, not representative of the vehicle's normal running conditions. As for catalytic converters, I thought Mitsubishi were developing lean burn engines when Thatcher bowed to lobbyists from Johnson Matthey etc, who wanted to make a killing with their platinum mining?

Traded in my diesel for a petrol after repeated DPF issues. Consider a DPFsectomy but the cost and legality as well as insurance "non standard vehicle" declaration made me buy a petrol. Will not go back to a diesel unless the car industry can make it work.

Can they now remove the additional taxes on diesel fuel. The UK is the only country in europe that has higher diesel prices than petrol. It would also reduce overall delivery costs benefiting manufacturers and consumers alike.

My car is over 7 years old, had recurring EGR & DPF problems under warranty which became very expensive afterwards, regeneration being a rarity. I had the DPF bypassed and a remap, fuel consumption improved significantly. My ignorance allowed me to think the less fuel I burn the better. Also, are the vapourised particles less toxic than the normal exhaust material? I do not wish to cause health problems but my car is more reliable, more economical and travels to the dealer for repair far less frequently.

I have a 4 year old BMW 520 diesel and after the filter blocked and went into what they call "limp mode" the car still drove so I took it to my local dealer a BMW specialist who offered to do the job, unfortunately because the DPF didn't regenerate it , the timing chain jumped a cog, which blocked the turbo! Result a repair coming to nearly £3000 ! Now ask me if I want to keep a diesel vehicle. In answer to the chap who seemed a bit peeved at old cars not having to have an mot, I have a very old vehicle that doesn't require an MOT but it's my labour of love and is looked after in such a meticulous way that most. MOT stations wouldn't have a clue where to start!

Surely the emissions element of the MOT test should determine a pass or fail, there should be no need to check if the DPF is present or for that matter functioning.

Same with EGR valves on petrol cars. I had a car just few years old very low mileage and thanks to the EGR valve the thing kept stalling. That was actually far more dangerous than any pollutants that may come out. Imagine doing a right hand turn on a busy road and the engine just cutting out with a truck fast approaching. The second car I got a VW had the same problem until I got fed up and disconnected the EGR control cable. The things are a nuisance and causing an engine to cut out in busy traffic randomly is very dangerous !!

A local country garage lad easily solved the problem of a blocked DFF filter on a friend's car.....remove it, boiling water, and it's O.K. Is that classed as "removing the DPF filter".? The government said they wanted to "save the motorist money" when they allowed pre-1960 vehicles to be free from MOTs: stupid reason, more likely the EU new MOT requirements can't be met by most, or they don't want a protest lobby to form......the FBHVC won't even keep the government to their promise to reintroduce the rolling date for Excise Duty (was 'road fund licence') on old, generally very low mileage vehicles concessions if elected. Conmen at every opportunity........and the FBHVC keep doing an 'ostrich act' on this one! Ask them why.......!

It is a disgrace to fail a vehicle for removing the DPF they cause more problems that can damage the vehicle than a lot of other things.

All wrong, DPF's cost a fortune when they fail same as fuel pumps and EGR valves. They were introduced to strangle the engine in order to meet legislation so were a last moment add on not an original design for the modern combustion engine. The government will take 20% of 1 k everytime the DPF's fail and that is why they introduced them. Our small cars are just as expensive to run now as a supercar 10 years ago because of tax and legislation. When will the public learn. It's all hype to make us believe the government are making a difference. How about the government does more about drugs and other items that kill the public and tax that instead!!!!!

Whilst this legislation is long overdue, there will be hugh problems involved in policing it to be effective, a visual check will not be sufficient

What about people buying second hand cars that have already had the DPF filter removed? The car would pass it's MOT currently so the new owner could be conned if they were not aware what a DPF looked like (or even knew what a DPF was!) I can see this harming the second hand diesel market once it becomes common knowledge...... some people just won't take the risk!

Removing the DPF is bad for the car, the design of a vehicle means that it is manufactured on the basis that all the components are correctly fitted and functioning. I use Revive Turbo Cleaner at every service and it keeps my car working fine. Best thing you can do is regular oil changes and like a comment above, get a petrol car for short jouneys ;-)

If all Britain's motorists stopped driving today it wouldn't make any measurable difference to world pollution. These deluded "Green" idiots are ruining the country, while, in the Far East, they're laughing all the way to the bank.

Dirty diesel cars cause people to die in this country. Micron small particles get into your lungs then your blood stream and you can't get rid of them. Great idea about time.

Surely the sensible solution would be if the car met the 'particular' requirement for the year of manufacture not if a certain gadget is in place. unfortunately politicians get it so wrong like catalytic converters. A lot better to have lean burn engines - strangely enough Thatcher favoured that, but she had a scientific background so better educated than the current and past muppets!

I work in the diagnostic field and how many cars I see with failed dpf, egr valves on diesel cars are amazing , then the customer says how much is it going to cost , around a grand and there face drops , then they say I only do 10k miles a year ! Why buy a diesel then. Good tip always buy a fuel efficient petrol car , less servicing costs and cheaper to buy fuel. If you have to run a diesel car get a induction clean ie terra clean/ bg products etc will keep the engine and dpf cleaner.

What a gang of muppets definitely worth 11% pay increase

With India and China planning to build 800 new coal fired power stations; I wonder if British motorists are being sacrificed on the altar of political correctness?

As usual the government is looking at things the wrong way. DPFs go wrong because of the way they work and are a very inefficient tool. People buy diesel vehicles for economy over the petrol equivalent, so it's stupid to put something in the exhaust to restrict flow. If the oil companies put as much effort into diesel refinery as they do with petrol then vehicle manufacturers wouldn't need to have put EGR valves or DPFs on their engines. The price of new cars would then be lower equaling more people affording them. It would also mean the fuel was of slightly better value considering it costs more than petrol here in the UK.

Another government scam game,another idiot that thinks. He knows what he's talking about I do wish people would think before they vote these idiots into positions of power no wonderthe country is going to the dog god help use.

Mine failed on my bmw and was removed it ran better and had such a low readout on the mot i rarely got a printout too close to zero. DPF and EGR have ruined diesel car reliability

How about the truth the garage charge an absolute fortune to replace DPF's That is why people remove them.