25/06/2026
🚗 Fiat Qubo 1.3 Multijet Diesel (2011) – Another Happy Customer! 👨🔧
Yesterday we attended this 2011 Fiat Qubo 1.3 Diesel which was suffering from poor performance and a heavily restricted DPF.
Before carrying out any cleaning, we always perform a full diagnostic assessment. On this vehicle we checked:
✅ Fault codes
✅ Live DPF differential pressure readings
✅ DPF soot load/calculated values
✅ Exhaust gas temperature sensors (EGTs)
✅ Turbo boost pressure (requested vs actual)
✅ EGR operation
✅ Airflow (MAF sensor)
✅ Fuel rail pressure
✅ Engine coolant temperature
✅ Regeneration status and ECU data
All of the relevant live data looked healthy except one thing…
The DPF back pressure was reading 201 mbar at idle.
That is an exceptionally high reading and is usually where we become very honest with our customers. At these figures there is no guarantee an on-vehicle clean will be successful.
There are several possibilities at this stage:
• The DPF could simply be heavily blocked with soot.
• The pressure pipes could be restricted with carbon deposits.
• The differential pressure sensor could be giving incorrect readings.
• Or the DPF may be heavily contaminated with ash, which unfortunately cannot be removed with an on-vehicle clean and usually requires specialist off-vehicle cleaning or replacement.
Rather than guessing, we verified the ECU reading using our digital manometer, which confirmed the back pressure was indeed 201 mbar.
After discussing all of the risks and possible outcomes with the customer, they decided they were happy to proceed.
Sometimes you have to take an educated gamble…
And on this occasion it paid off! 💪
The DPF responded exceptionally well to the cleaning process and, to our surprise, the vehicle actually initiated its own regeneration while idling—a great sign that the exhaust system was flowing correctly again.
📉 Before cleaning:
201 mbar back pressure
📈 After cleaning:
7.5 mbar back pressure
That’s a massive improvement.
The customer took the vehicle for a road test and came back with a huge smile on their face. The power was restored, the vehicle drove like it should, and they said it felt like a completely different car.
This is exactly why we diagnose first and clean second. We don’t believe in simply selling a DPF clean—we believe in giving our customers the facts so they can make an informed decision.
If your diesel has:
🚗 DPF warnings
🚗 Loss of power
🚗 Limp mode
🚗 Frequent regenerations
🚗 Excessive back pressure
Get in touch with HCR Performance for honest mobile diagnostics and DPF solutions.
