DPF Faults

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Diesel particulate filters (known as DPF's) became a legal requirement for diesel vehicles in 2009, their function is to help reduce harmful exhaust emissions by trapping soot particles. If you own a diesel vehicle what you may not realise is that by design, the DPF is not meant to last the lifetime of your vehicle, with proper maintenance and good practice a DPF can last around 100k miles but many diesel owners start to encounter issues at around 50k miles, the lifetime of the DPF can be further shortened by improper maintenance, poor quality engine oils and short journeys.  

The thinking behind the DPF is that as your use your vehicle, soot will accumulate in the filter and once it's full, you'll return your vehicle to the main dealer where they'll fit a new DPF, that sounds reasonable in theory but in practice, new DPF's can cost thousands, fortunately there are a range of cost effective aftermarket solutions now available to us.

Firstly, don't ignore it, if the DPF warning light has come on it doesn't necessarily mean there's a fault, it could be that your vehicle just needs a little help entering it's passive regeneration mode, this typically involves driving your vehicle on a longer journey of 20-30 minutes, this will vary from vehicle to vehicle so you should consult your vehicle hand book for more information.

If your vehicle is unable to self regenerate and the DPF warning light has remained on, it's time to get it touch.

Before you go putting anything in your vehicle's fuel tank, speak to us first, some in-tank DPF fuel additives can cause harm if used incorrectly, many of the DPF additives for sale work by creating a chemical reaction which increases the temperature within your vehicles DPF, however, if your DPF is partially blocked, the temperature within the DPF will already be heightened, in such circumstances increasing the temperature further by using an additive will likely damage the DPF beyond repair. 

If you ignore the DPF warning light, in time additional lights and symbols may become illuminated on your vehicle's dashboard and your vehicle will likely experience a reduction in power.

Eventually the DPF will become completely blocked, if this happens your vehicle will require a new DPF which can cost anywhere from a few hundred to a few thousand pounds, a blocked DPF can also cause significant harm to other engine components.

No, you should not remove the DPF from your vehicle, the act of removing the DPF from a vehicle is not by itself illegal which is why you'll see many companies offering this service, however, using a vehicle on the road with the DPF removed is illegal with penalties of up to £1000 for cars and £2500 for vans.

It's easy to spot a diesel vehicle with the DPF removed as they emit visible exhaust smoke and there are usually signs the DPF has been tampered with, since 2018 MOT testing rules have become much more stringent with MOT testers now required to check for evidence the DPF has been cut open and welded, should the tester believe the DPF has been tampered with, they will refuse to issue an MOT test certificate for the vehicle as a missing or tampered with DPF is a major failure.