DPF cleaning vs replacement: which is right for your diesel?
When a clean works, when it doesn't, and the price gap between the two.
Your diesel particulate filter (DPF) traps soot from the exhaust. Over time it fills up. The car is supposed to “regenerate” it automatically by burning the soot off at high exhaust temperature — but city-driven diesels never get hot enough, and the filter blocks. Then what?
Option 1: Clean
Cleaning works on most blocked DPFs. There are two methods:
- Forced regeneration — done with a manufacturer-specific diagnostic tool. The tool tells the engine to run hot for 30 minutes while the DPF burns off the soot. €150 typical, sometimes effective on partially blocked filters.
- Off-car ultrasonic cleaning — DPF removed from the car, ultrasonic-bath cleaned, re-fitted. €200–€350 typical, very effective even on heavily blocked filters.
Option 2: Replacement
A new OEM DPF is €1,500–€3,500 depending on car. Replacement is the right choice when:
- The DPF is melted internally (no cleaning will help)
- The substrate is cracked (visible on inspection)
- Cleaning has been tried and the filter blocks again within a few thousand km
Replacement is not the first option for a routine block — too expensive when cleaning works.
Option 3: Software delete (don’t)
Some garages offer “DPF delete” — physically removing the filter and remapping the ECU to ignore it. This is illegal in Ireland — the car will fail NCT and the modification may also invalidate insurance. We don’t do it.
What we do at V.T. Motors
- Diagnostic scan to confirm the DPF is the issue (sometimes it’s a sensor)
- Try forced regeneration first
- If that fails, off-car ultrasonic clean
- If that fails, replacement is recommended with a written quote
- We log every step so you have a record
Book DPF cleaning — phone 01 847 5146.