Diesel Particulate Filters (DPFs) are engineered to trap and remove harmful soot particles, known as particulate matter (PM), from diesel exhausts. Acting like high precision sieves, they prevent these pollutants from entering the atmosphere and help vehicles meet stringent emissions standards.

DPFs don’t just trap PM they also clean themselves through a process called regeneration. When PM levels reach around 60%, the engine control unit (ECU) initiates regeneration, injecting additional fuel to heat the DPF above 550°C and burn off accumulated soot.

However, regeneration may not occur if the engine experiences:

• Poor maintenance
• Turbocharger or injector faults
• Faulty pressure or temperature sensors
• Condensation in sensor pipes
• Faulty EGR valve
• Damaged exhaust system (low/high back pressure)
• Air leaks upstream of the DPF
• Use of incorrect fuel or engine oil

Regeneration can also lead to diesel contaminating the engine oil. If this happens, it’s essential to replace the engine oil and filter. Regeneration will not take place if the EML light is illuminated, and sealants must not be used upstream of a catalyst or DPF.

To support proper regeneration:

• Inspect pressure pipes for damage or debris
• Verify the EGR system is functioning correctly
• Use manufacturer-recommended engine oil
• Check for diesel contamination in the engine oil
• Ensure sufficient fuel additive levels where required
• Check the fuel vaporiser on relevant models (e.g., Ford vehicles)
• Follow all manufacturer/factory protocols outlined in the handbook

Blocked DPFs are not covered under warranty, making prevention and proper maintenance critical.

At EEC, we are dedicated to helping technicians meet the challenges of modern emissions management. With a growing range of high quality DPFs and our in house wash coating facility in Denmead, we deliver excellence to both domestic and export markets. Through our comprehensive education and training programs, we empower industry professionals to diagnose, maintain, and resolve emission issues with confidence and precision.

To view our newest range of DPF please click here.