Short answer

You can help a DPF clean itself by letting it regenerate on a sustained drive, use a DPF cleaner additive or on-vehicle cleaning fluid for a moderate soot load, or have it cleaned off the vehicle by a specialist to remove ash. Diagnose the cause first, or the filter will block again.

On this page

“Cleaning a DPF” can mean anything from a good drive to a full workshop clean. This guide sets out the options in order, from cheapest and least invasive to most thorough, so you can choose the right one for your filter.

First, why did it block?

A DPF that blocks has usually been unable to regenerate. Short journeys are the most common reason, but faulty pressure sensors or hoses, injector or EGR faults and the wrong engine oil all contribute. Cleaning without fixing the cause rarely lasts. See DPF problems and symptoms.

Option 1: let it regenerate

If the DPF light is steady and there are no other warnings, a sustained drive at steady speed often lets active regeneration clear the soot. This costs nothing but time.

Option 2: additives and on-vehicle cleaning fluids

DPF cleaners help soot burn. A tank additive suits prevention and light soot loads. On-vehicle cleaning fluids are injected into the filter, usually through a sensor port, before a forced regeneration. Neither removes ash.

Option 3: forced regeneration

A workshop can run a forced regeneration with a diagnostic tool. It is effective for soot but must not be attempted on a severely overloaded filter, which can overheat.

Option 4: professional off-vehicle cleaning

For an ash-loaded or heavily blocked filter, removal and cleaning on dedicated equipment is the only method that restores the full capacity. A proper service includes flow tests before and after. See DPF cleaning and DPF cleaning cost.

How to clean a DPF, step by step

  1. Check for fault codes

    Read codes and soot load with a scanner. If there is a sensor or engine fault, fix it first.

  2. Try a regeneration drive

    If the load is mainly soot and the handbook allows, a sustained drive at steady speed lets active regeneration finish.

  3. Use an additive or cleaning fluid

    For a moderate soot load, follow the product instructions exactly, then complete a regeneration.

  4. Force a regeneration if needed

    With a suitable diagnostic tool, once the filter is confirmed safe to regenerate.

  5. Book off-vehicle cleaning for ash

    If the filter is ash-loaded, packed solid or keeps blocking, have it removed, thermally cleaned and flow-tested.

  6. Reset and verify

    After any clean, reset soot/ash values where required and confirm normal differential pressure.