What the DPF and EGR do
The DPF traps soot from a diesel exhaust and burns it off periodically in a process called regeneration. The EGR valve recirculates a portion of exhaust gas to reduce emissions. Both can clog or fail.
Common causes of faults
Short journeys that never allow regeneration, a faulty sensor or EGR valve, injector or turbo problems, and poor oil or fuel quality are common causes. Treating the symptom without finding the cause usually means the fault returns.
What can be done
- Diagnosis to find the underlying fault
- DPF cleaning to remove trapped soot and ash
- EGR valve cleaning or replacement
- Repair or replacement of the failing sensor, injector or turbo
- A longer motorway drive to complete a regeneration, if the system is healthy
Warning signs to act on
Do not ignore these: they usually get more expensive the longer they are left.
- A DPF or engine warning light on the dashboard
- The car dropping into limp mode with reduced power
- A smell of hot exhaust or fuel, or a rising oil level on a diesel
- Frequent, unsuccessful regeneration attempts, or the cooling fan running after you switch off
- Noticeably poorer economy or rough running
How to reduce the chance of problems
Take the car for a longer run at steady speed now and then so the filter can regenerate, keep to the service schedule, use the correct low-ash oil for your engine, and have warning lights checked early rather than clearing them.
Why removal is not an option
Removing or defeating a DPF or EGR system on a road vehicle is illegal in the UK and a vehicle with its DPF removed will fail the MOT. Remap Experts does not offer or promote it. Our DPF and EGR services are diagnostic, cleaning and repair work only.
Questions
Can you remove my DPF?
No. Removal is illegal on road vehicles. We diagnose, clean and repair DPF and EGR systems instead.
Will a remap fix a DPF fault?
No. A remap does not repair a failing DPF or EGR. The fault should be diagnosed and fixed first.