Diagnose
We read the fault codes and live data — soot load, differential pressure, temperatures — to understand why the filter is blocking.
DPF cleaning
Blocked DPF? Fix the cause, not just the light.
A diesel particulate filter rarely blocks for no reason. We diagnose why it’s happening, clean the filter, and help make sure it doesn’t simply block again.
How a DPF works
A filter that needs the right conditions to clean itself
Since the late 2000s most diesel cars and vans have been fitted with a diesel particulate filter (DPF) to trap harmful soot. As soot builds up, the vehicle raises the exhaust temperature to burn it off — a process called regeneration.
Regeneration works best during a steady, longer drive. Lots of short trips, stop-start traffic and low-speed driving can interrupt it, and soot keeps accumulating until a warning light appears or the engine drops into reduced power.
Cleaning restores the filter, but if something is making the engine produce extra soot — or stopping the regeneration from completing — the problem will come back. That’s why we start with diagnostics.
Symptoms
Signs of a blocked DPF
Don’t ignore a DPF warning. Driving for long periods with a heavily blocked filter can lead to more expensive problems.
- DPF warning light on the dashboard
- Reduced power or limp mode
- Engine management light alongside the DPF light
- Frequent or failed regenerations
- Higher fuel consumption
- Cooling fan running after the engine is switched off
Our approach
Diagnose, clean, prevent
Clean
We clean the DPF to restore exhaust flow and bring soot levels back to where they should be.
Prevent
We explain what caused the blockage and what will help — from repairs to simple changes in how the vehicle is used.
Every case is different. A filter that is badly damaged or cracked may need replacing rather than cleaning. We’ll tell you what we find and talk through the options before going ahead.
Questions
DPF questions
If your question is about a specific vehicle, the quickest answer is usually a call.
What does a DPF do?
A diesel particulate filter traps the soot produced by a diesel engine so it doesn’t leave the exhaust. The trapped soot is burned off periodically in a process called regeneration, which usually needs sustained driving at higher engine speeds.
Why do DPFs block?
Mostly through short journeys and low-speed driving, which don’t let the filter get hot enough to regenerate. Underlying faults — such as a faulty pressure sensor, EGR problems, injector issues or the wrong engine oil — can also cause soot to build up faster than it can be cleared.
My DPF warning light is on. What should I do?
Check your handbook first — some vehicles ask for a sustained drive to allow a regeneration. If the light stays on, returns quickly, or the vehicle goes into reduced power, get it checked. Continuing to drive with a blocked DPF can lead to more expensive problems. See our DPF cleaning page.
Can a DPF be removed instead?
Not legally on a road vehicle. Removing or tampering with a DPF is illegal in the UK and causes an MOT failure. Cleaning the filter and fixing the reason it blocked is the right long-term answer.
Talk to Retroworks
Sort the DPF problem properly.
Tell us about the warning lights and how the vehicle is behaving, and we’ll advise on the next step.
Keep exploring
Related services
Dealer-Level Diagnostics
Warning lights and faults investigated with dealer-level diagnostic equipment.
Find out more
Vehicle Remapping
ECU calibration tailored to your vehicle, focused on power delivery, torque and drivability.
Find out more
Servicing & Repairs
Routine servicing and mechanical repairs, at our workshop or at your home or work.
Find out more