Has your DPF Warning light come on? Here are some of the most common questions we get asked.

What is the DPF? The DPF or Diesel Particulate Filter is a device which traps carbon soot and ash particles as they travel through the exhaust. By trapping and storing exhaust soot the filter will initiate a regeneration process and burn off the excess soot and ash stored, thus helping prevent harmful exhaust emissions.

The DPF device is normally made from a honeycomb ceramic structure which helps gather particles. Over time, excess carbon will build up and the regeneration process may not be performed correctly resulting in a ‘DPF warning light’.

• DPF consists of a honeycomb-shaped ceramic body with open and closed channels
• Exhaust gas passes across open channels and is filtered through closed channels trapping PM inside
• As the soot loading increases, the system will look to carry out regeneration. Normally around 45%

Qu: Will driving up the motorway turn off the DPF warning light if the DPF is blocked?

An: A quick blast up the motorway does not always work and instead a longer regular driving should be encouraged. The difficulty is if a vehicle is driven on very short, start-stop journeys then the DPF may not regenerate.

Qu: When my DPF warning light comes on what does this mean?

An: Firstly this could mean there’s a blockage. Carbon soot can build up over time which will trigger the warning light when the DPF becomes blocked. There could also be a fault with the emissions control system. If a vehicle has been driven largely on short journeys then the DPF may not have regenerated correctly.

Qu: In order to treat a DPF symptom what Wynn’s products should be used?

An: Wynn’s DPF (Diesel Particulate Filter) Cleaner 325ml added to the fuel tank, helps burn soot at a lower temperature, protecting the filter and reducing ash build up. Wynn’s DPF (Diesel Particulate Filter) Cleaner 325ml uses cerium as a catalyst to help burn carbon build up.

Wynn’s DPF (Diesel Particulate Filter) Cleaner 325ml is an iron-based additive which helps raise the temperature in the filter. Follow the instructions carefully and, if in doubt before using it, please contact Skinny Tree for further help.

The image above shows a example of a diesel particulate filter before (left) and one after a treatment with Wynn’s DPF (Diesel Particulate Filter) Cleaner 325ml (right). Visibly less build up of ash and soot can be seen once treated.

Qu: The warning light is still on after using Wynn’s DPF (Diesel Particulate Filter) Cleaner 325ml?

An: We like to take a cautious view and suggest seeking further help and investigation by a DPF specialist. Regen formulas such as the Wynn’s DPF (Diesel Particulate Filter) Cleaner 325ml will provide treatment and help reduce carbon build ups however from time to time the problem may not be resolved through a fuel treatment. Continually driving a vehicle with a DPF warning light could send the vehicle into limp mode.

Official UK Wynns’s stockist