DPF-FAP Solutions

Diesel Particulate Filter (DPF) and FAP Solutions

What is a DPF or FAP?

A Diesel Particulate Filter (DPF), also known as Filtre à Particules (FAP), is a filter located in the exhaust system of diesel vehicles. Its primary purpose is to reduce the amount of Diesel Particulate Matter (soot/ash) emitted into the atmosphere. By capturing these particles, DPFs contribute to cleaner and more environmentally friendly exhaust gases.

Common Problems with Blocked DPFs:

  1. Loss of Power: A blocked DPF can lead to reduced engine performance and sluggish acceleration.
  2. Poor Fuel Economy: Increased backpressure caused by a clogged filter affects fuel efficiency.
  3. Throttle Response Issues: Blocked DPFs may cause delayed throttle response.
  4. Engine Start Failures: Severely blocked filters can prevent the engine from starting.

Underlying Causes of DPF Blockage:

  1. Short Journeys: Frequent city driving prevents the DPF from reaching optimal operating temperatures required for regeneration.
  2. Faulty Sensors: Sensors monitoring pre- and post-filter temperature and pressure play a crucial role in regeneration. Sensor failures can hinder effective regeneration.
  3. EGR Valve Issues: A malfunctioning Exhaust Gas Recirculation (EGR) valve can increase exhaust gas flow through the DPF, accelerating blockage.
  4. Swirl Flap Problems: Similar to the EGR valve, faulty swirl flaps impact emissions control and DPF health.


  1. Forced Regeneration: Attempt a forced regeneration to clear the DPF. This process involves raising exhaust temperatures to burn off accumulated soot.
  2. Diagnostics and Repair: Expert diagnostics can identify underlying issues causing DPF blockage. Addressing these root causes is essential.
  3. DPF Removal: In extreme cases, consider DPF removal. However, this option may not comply with emissions regulations and can impact the environment.

Remember that proper maintenance and addressing underlying issues are crucial for DPF longevity and optimal performance. If you suspect DPF-related problems, consult a professional mechanic for accurate diagnosis and appropriate solutions.

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