If you own a diesel car you probably have a DPF or know what they are
Diesel particulate filters have been fitted to diesel fuelled cars for almost two decades now – but if not maintained, or if tampered with there could be serious consequences for your car and you
This article is to explain exactly what they are, what they do, why they are fitted and how to look after them. Used properly they rarely cause problems or need replaced
We do offer cleaning services for DPFs and will mention this later
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What is a diesel particulate filter?
A diesel particulate filter (DPF) captures and stores exhaust soot in order to reduce emissions from diesel cars. Because they only have a finite capacity, this trapped soot periodically has to be emptied or ‘burned off’ to regenerate the DPF
This regeneration process cleanly burns off the excess soot deposited in the filter, reducing the harmful exhaust emission and helps to prevent the tell-tale black smoke you used to see from diesel vehicles, particularly when accelerating
Euro 5 exhaust emissions legislation introduced in 2009 to help lower car CO2 emissions effectively made DPFs mandatory, and since then, around one in two new cars a year have been diesel-powered.
What does a regeneration do ?
What does a DPF regen do?
Whatever the car, the process works in much the same way: exhaust gases pass through the filter, leaving large soot particles behind. And it’s these particles that can cause problems. The soot can block the filter, stopping the engine from running and leaving you with a repair bill running into the thousands.
To stop this from happening, the soot needs to be burned at a high enough temperature to turn it into smaller ash particles, which can then be expelled from the system. It’s when this cleaning, or ‘regeneration’, process is interrupted that the majority of issues with DPFs occur.
This process of emptying the soot is called DPF regeneration. The soot created by the process of combustion which is collected in the filter is burnt off to make sure that the filter does not become blocked and that it can keep taking the soot out of the exhaust fumes
Your user manual will give exact advice for your car but most involve immediately take the car out on a dual carriageway or motorway for 15 minutes of continuous driving to give the DPF an opportunity to regenerate
Is it illegal to drive a car that has had a diesel particulate filter removed ?
Yes, it is illegal. Owners face fines if caught (up to £1,000 for cars and £2,500 for vans) and removing a DPF means the car is no longer legal to use on the road. Insurance companies are not allowed to insure modifications that are not road legal.
If you have had yours removed and have not been made aware of the legal issues it can cause you need to take this up with the person or business who removed it. Driving a car without insurance can have serious consequences. An insurance company can not insure a modification for road use that is illegal, so owners won’t have insurance
What does DPF cleaning do ?
Our DPF cleaning is offered as 2 options one we don’t need to remove the DPF from the car and has an 80% success rate. Removing and soaking the DPF is more successful for those with a serious blockage. We have only not been able to successfully clean one in this way in 5 years