Citroen C6 Diesel Particulate Filter DPF (2005-2012)

The Diesel Particulate Filter (DPF) on Citroën C6 diesel models (including 2.7 HDi 204 hp and 3.0 HDi 241 hp) is an anti-pollution device that traps fine particles from the exhaust gases. It uses a porous silicon carbide structure with a filtration threshold of 0.1 micron, forcing exhaust gases through the filter walls to capture particulate matter, helping reduce emissions and environmental pollution.

The DPF system works by heating the exhaust gases to burn off accumulated soot particles. The vehicle's onboard computer monitors the filter's differential pressure and activates regeneration processes to clean the filter when needed. Key regeneration types include:

• Level 1: Heating the catalytic converter to activate it while maintaining constant torque and adjusting air intake airflow.
• Passive regeneration: Occurs during long, fast driving when exhaust temperature naturally burns the soot.
• Active regeneration: A forced cleaning including post-injection of fuel and raising engine speed to 4000 rpm after brief idling.

The system also doses an additive (such as Eolys) to assist regeneration, monitored by the onboard computer to prevent clogging.

Common Citroën C6 diesel models equipped with DPF include:

• 2.7 HDi (TD) – 204 hp, produced between 2005/09 and 2009/02. Diesel DPF replacement available.
• 3.0 HDi 241 hp (DT20C, V6 biturbo) – Requires specific cleaning additives and maintenance aerosols for optimal performance.

Always verify engine codes and compatibility through your vehicle VIN when looking for replacement parts or maintenance products.

Signs of a clogged DPF include:

• The engine’s maximum rpm is limited to around 2200 rpm as a protective measure.
• A warning light appears on the dashboard.
• Reduced engine performance and increased fuel consumption.

If these symptoms occur, it is crucial to perform diagnostics and potentially carry out a forced regeneration or cleaning procedure as soon as possible.

Maintenance and care options include:

• Chemical cleaning: Using fuel additives to clean the DPF, injection system, and combustion chamber deeply.
• Forced regeneration: Performed using diagnostic tools to burn away soot, clean or replace the DPF, refill additive reservoirs, and reset error codes.
• Carbon cleaning: Removes deposits from EGR and engine components to restore performance and fuel efficiency.
• Use of specific aerosols: Products like 400 ml sprays designed for 3.0 HDi DPF maintenance.

Regular highway driving with sustained speed helps keep the DPF healthy by enabling passive regeneration.

The DPF system uses an additive such as Eolys, which is dosed by the vehicle’s computer to enhance the regeneration process. Key points include:

• The additive tank level must be monitored and refilled as required to avoid filter clogging.
• The additive helps lower the temperature needed to burn off soot during regeneration.
• Used additive must be recycled properly during maintenance or part replacement.

Failure to maintain the additive level or disruption of regeneration can lead to engine warnings and reduced performance.

To maintain DPF health, it is recommended to:

• Drive at sustained speeds on highways or open roads regularly to enable passive regeneration through high exhaust temperatures.
• Avoid only short journeys that prevent the engine and DPF from reaching optimal operating temperature.
• Follow any on-board computer recommendations or warning lights to initiate regeneration sequences.

Ignoring these conditions may cause premature clogging and damage the DPF and engine.

Quality new DPFs are available that comply with manufacturer specifications and European regulations. When selecting a DPF replacement, consider the following:

• Look for products made from high-grade ceramics and stainless steel for durability.
• Choose DPFs certified by recognized bodies such as TÜV SÜD, ensuring performance equal or superior to original parts.
• Verify compatibility by providing your vehicle VIN and engine codes when ordering.
• Professional installation and following manufacturer instructions are essential to maintain warranty coverage.

Always seek technical support and verified installation manuals from trusted sources or your garage specialized in exhaust systems.