Citroen C4 Diesel Particulate Filter DPF

The DPF is an essential pollution control device located on the exhaust line after the catalytic converter of your Citroën C4 diesel engine. It is made from durable ceramic material designed to capture and remove fine soot particles produced during diesel combustion, reducing harmful emissions.

The DPF uses a system of alternating channels to trap particles:

• Entry channels allow exhaust gases to enter but are blocked at the exit
• Exit channels let purified gases escape but are blocked at the entry
• The gases are forced to pass through porous walls that trap soot particles

This effectively reduces particulate emissions from your car’s exhaust.

DPF regeneration is the process where trapped soot is burned off to clean the filter and maintain performance. There are two types:

• Passive regeneration: Happens naturally when exhaust gases reach around 550 to 600°C during high load driving conditions, such as motorway journeys.
• Active regeneration: Triggered by the engine management system during low temperature conditions (like urban driving), injecting fuel into the exhaust to raise the filter temperature and burn off particulates.

Citroën’s system uses a fuel additive to lower the combustion temperature of particles to about 450°C, improving regeneration efficiency.

Typically, the DPF needs cleaning or replacement between 120,000 and 180,000 kilometres depending on driving habits and maintenance. On models like the C4 Picasso 1.6 HDi, the DPF is located under the vehicle floor, after the catalytic converter, and in newer models may be integrated with the catalytic converter in one unit.

To extend the DPF’s life and ensure effective regeneration:

• Regularly drive at higher engine temperatures, such as steady motorway runs at over 3000 rpm
• Use suitable fuel additives that help keep the DPF clean
• Follow your vehicle’s scheduled maintenance strictly

These practices help prevent clogging and maintain emission performance.

Yes, professional cleaning methods exist that do not require dismantling the DPF. One advanced technique uses hydrodynamics where exhaust gas pressure creates shock waves to dissolve soot, ash, and other deposits, effectively rinsing the filter inside and out.

• Removes soot, ash, and ceriumn oxide
• Restores original filter performance and fuel efficiency
• Reduces smoke emissions and assists passing MOT tests
• Preserves engine longevity

This method is efficient and recommended for DPF maintenance.

Some Citroën C4 models display a “Risk of filter clogging” warning message around 160,000 km, which might appear without an actual sensor fault. A professional can reset this alert if no problem is found. Other messages such as “Check DPF system” indicate the need for a thorough diagnostic to identify and resolve any issues.

• Warnings help protect engine health by alerting to DPF problems
• Prompt attention can avoid costly repairs or replacements

Always consult a qualified technician for these alerts.

The DPF was implemented to meet environmental standards starting with the Euro IV regulation, which halved allowable particulate emissions compared to Euro III. It enables your Citroën C4 to comply with today’s strict emission limits and contributes to reducing pollution for a cleaner environment.

• DPF technology aligns with European legislation for emission control
• Helps reduce harmful diesel particulate emissions from the vehicle fleet

Maintaining your DPF ensures your car remains compliant and eco-friendly.

For technical inquiries and original quality DPF replacements, consider certified products to maintain optimal performance and emission standards.