Peugeot Expert Diesel Particulate Filter DPF

The Diesel Particulate Filter (DPF) on the Peugeot Expert is an essential part of the diesel engine's exhaust system. Installed after the catalytic converter, it traps solid particles (soot) from combustion, reducing fine particle emissions by up to 99% in compliance with Euro 5 and Euro 6 standards. It consists of a ceramic honeycomb structure that forces exhaust gases through porous walls, capturing soot while allowing gases to pass through.

The DPF on the Peugeot Expert is located on the exhaust line after the catalytic converter and is accessible for maintenance. It is made from a ceramic substrate, such as cordierite, designed to be porous enough to let gases flow through while trapping solid particles. The DPF is housed in stainless steel INOX 409 casing for durability.

The DPF collects soot particles during engine operation, gradually becoming clogged especially in city or short trips with low exhaust temperatures below 550°C. Regeneration burns off the soot turning it into harmless ash:

• Passive Regeneration: Occurs naturally during highway or high-load driving when exhaust gases reach 550-600°C, burning soot continuously.
• Active Regeneration: Triggered by the engine control unit when soot load is excessive, injecting fuel post-catalytic converter to raise temperature around 600°C to burn soot actively.

Regeneration frequency depends on driving conditions, air mass, fuel injection, exhaust temperature, and pressure sensor readings.

The DPF system uses a differential pressure sensor connected by flexible lines to measure pressure before and after the filter. This sensor informs the engine control unit about the soot load and backpressure which affects the engine’s performance and triggers regeneration or warning lights if needed.

• Pressure differential above 160-300 mbar indicates excessive soot.
• Sensor or hose failures can lead to pressure readings outside normal range, signaling potential DPF issues.

Signs of a clogged DPF include:

• Reduced vehicle speed limitation (e.g., limited to 60 km/h)
• Warning light on the dashboard indicating "DPF clogged" or "FAP encrassé"
• Continuous operation of the cooling fan due to increased engine load
• High differential pressure readings beyond normal limits

Ignoring these warnings may risk engine damage and higher fuel consumption.

DPF diagnosis with a diagnostic tool is done with the ignition off and engine warmed to at least 80°C. Normal pressure values in mbar are:

• Ignition off (static): 0-5 mbar (higher suggests sensor or wiring fault)
• Engine warm at idle: 0-10 mbar (higher may indicate clogged DPF or hose leaks)
• At 3000 rpm for engines under 2L: 20-60 mbar
• At 3000 rpm for engines over 2L: 70-90 mbar (up to 160-300 mbar during regeneration)

Abnormal values require inspection of electrical wiring, hoses, and DPF status to avoid irreversible clogging by ash.

To maintain your Peugeot Expert’s DPF and prevent clogging:

• Prefer long-distance and highway driving to enable passive regeneration.
• Use lubricants and fuels formulated to reduce ash derived from oil additives.
• Address any warning lights promptly with proper diagnostic checks.
• Ensure timely replacement of the DPF when severely clogged; procedures require expert removal of the exhaust line and insertion of a new ceramic unit.
• Regularly check and replace sensors and hoses associated with the DPF system.

Warning lights or messages on the dashboard should never be ignored as they warn of a clogged DPF which risks:

• Reduced engine power and speed limitations
• Increased exhaust backpressure, which can damage the engine
• Higher fuel consumption and associated costs
• Potential risk of permanent DPF damage requiring costly replacement
• Warning light "DPF warning" or "DPF issue" indicates cleaning or replacement may be required

Seek professional garage assistance with diagnostic tools (like PP2000/LEXIA) to properly check, clean, or replace the DPF to maintain engine and environmental performance.