DPF Removal?


Driving without a DPF Filter can be against the law and quite unnecessary

Diesel particulate filters (DPF) are placed on the exhausts of diesel vehicles to prevent toxic emissions from flowing into the environment. So, why are so many diesel car owners removing them and why haven’t sites, such as eBay, Google, and Gumtree, banned advertisements for these services?

I will tell you how you can regenerate your DPF Filter without spending  a penny. More on that in a moment…
diesel particulate filter image
Already, more than 1,000 diesel car owners have been caught removing the filter, though experts believe that the problem is much more prevalent.

Recently, campaigners have started to voice their complaints to the Advertising Standards Authority (ASA). They argue that allowing advertisements for DPFs is breaking the ASA code, which bans motoring “practices that condone or encourage anti-social behaviour”. The adverts are exploiting a loophole in the law, which states that driving a diesel car without a DPF is an offence, yet the actual act of removing it is not.

In the past week, MPs have labeled air pollution to be a “public health emergency”. In fact, particulate pollution is responsible for between 40,000 and 50,000 early deaths in the UK each year. Despite this, many repair garages throughout the UK continue to offer to remove DPFs. MPs have labelled this practice as “clearly detrimental to people’s health” and “unacceptable”.

Why Are People Removing DPFs?

These filters easily become clogged, especially when driven by vehicles in the city. Town and city cars will often be driven at low speeds in residential areas without ever getting a motorway run that can often unclog the DPF filter and regenerate it.

Replacements tend to be expensive, which is why many of the UK’s top garages have offered to take them off completely. Google and Gumtree have stated that they accept these adverts because the actual removal service itself is not against the law.

Since 2014, any diesel vehicle missing a diesel particulate filter automatically fails the MOT. In late April, the Guardian revealed that so far 1,188 vehicles have been caught without a DPF. However, some garages in the area post on their websites that they can beat the visual MOT check.

Friends of the Earth (FoE)

Founded in 1971, FoE is a federation of 74 groups from all over the world who are dedicated to saving the environment. One of their primary causes involves complaining to the ASA about the prevalence of adverts for DPF removal services.

In a press release from 2 May 2016, FOE air pollution campaigner, Oliver Hayes, stated, “Air pollution is a public health crisis of breath-taking proportions. The dodgy practice of removing pollution filters from cars is not only risking people’s health, but also putting drivers at risk of prosecution for the simple fact that it’s illegal to drive a car with its DPF removed.”

He went on to say, “We’re asking the ASA to clamp down on those advertising these dubious practices … But we’re also calling on the Government to make it illegal to remove these pollution filters in the first place”.

Chaired by Mary Creagh MP, the House of Commons Environment Audit Committee is currently investigating diesel emissions and air quality. She states, “The Department of Transportation did the right thing in introducing visual checks into MOTs. But it should now look at tightening up MOTs and outlawing the removal of pollution filters altogether”.

What Does Google and Gumtree Have to Say?

When contacted by the Guardian, Google simply stated it didn’t comment on individual cases and were not inclined to remove adverts for DPF removal. A spokesperson stated, “Our policies require advertisers to comply with all applicable laws and local regulations. If we discover sites or services that are in violation of this policy we take appropriate action.”

Gumtree had a similar response. According to Hannah Wilson, Head of Marketing at Gumtree, “Our policy for posting adverts on Gumtree is based on compliance with English law. As there are sometimes legitimate reasons for the removal of diesel particulate filters, and the removal of DPF is not an offence, then these services can be offered by advertisers via Gumtree. If the practice of removing DPFs was outlawed, then we would immediately ban and remove these listings from the site.”

Although eBay was contacted several times for comment, the site never responded.

Keep in mind that it is legal to remove, clean, and replace DPFs and there are plenty of adverts for this legitimate service. The problems lies with garages that advertise “DPF removal services” that clearly indicate the filter will be removed, but not replaced.

How do I fix my DPF Filter without spending a penny?

In 2014 I bought a Vauxhall Zafira diesel automatic, with a DPF filter fitted as standard. As I was driving the car from Southhampton to Bristol the engines glow plug light began flashing. Different cars will illuminate different warning lights as you can see in the image below.
image of a DPF Filter warning light
The car was running just fine, although it was drinking a lot of diesel.

My mechanic diagnosed that the DPF filter was faulty and needed replacing. The trade cost to supply and fit the filter was £918 + VAT. This cost was going to eat all of my profit when I sold the vehicle.

As I have mentioned, DPF Filters often block and degenerate when a car is primarily driven around town and doesn’t get a good motorway run from time to time.
My Zafira was in excellent condition and may have been previously owned by a very careful driver that rarely revved the engine. This led me to attempt my own DPF unblock, without touching a spanner.

You may have heard that you can regenerate a DPF Filter by giving the car a run down the motorway. Unfortunately this rarely works because the cars filter is so badly blocked that a replacement may seem to be the only remedy.

How to unblock almost any DPF Filter

Here’s how I permanently unblocked the DPF on my Vauxhall Zafira (and many other cars too)

If you follow my instructions you will probably unblock your cars filter and never have to spend a penny to fix it.

It’s quite simple. Drive your car on the motor way at extremely high revs for at least 30 minutes. By high revs I mean at least 5,000 RPM. It can be a  little unnerving to hear your car working so hard, but believe me it works. If you have a manual car I suggest second gear and a speed of around 50 mph. You can try third gear at around 80 mph but that’s illegal so I’m not really advising that you do that. If you have an automatic select the auto second gear position and drive the engine up to 5,000 rpm.

It’s very important that you consistently hold the revs and speed for at least 30 minutes (preferably more.) If you do this correctly your filter will almost certainly unblock itself.

Once you have run the car very hot for a sustained period of time pull over and immediately switch off the car. Wait for a short while before restarting your car to find that the DPF warning light, glow plug light or engine management light are now switched off!

By running your car in this manner you regenerate the DPF Filter and unclog all the soot and dirt that’s built up over time.

Please ensure you’ve sufficient engine oil in the car before trying this, else you could bend some engine valves and that will cost even more money.

Note – Once your car is back to its old self it’s important to give it a good blast every week or the light may very well come back on in the future.

The Used Car Guy holds no liability for your outcomes when trying the procedure listed above. This article is meant only to aid car owners that wish to avoid spending large amounts of money on their used car.

The Used Car Guy

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