How does a Diesel Particulate Filter (DPF) regeneration work?

DPF regeneration burns off accumulated soot using high temperatures (550-650C). Passive regeneration occurs naturally during high-load driving when exhaust is hot enough. Active regeneration is triggered by the ECU when soot loading reaches threshold, using post-injection of fuel that combusts on an oxidation catalyst to raise exhaust temperature. Some systems also use a fuel-borne catalyst. Regeneration frequency depends on driving conditions, with frequent short trips requiring more active regeneration. Forced regeneration with scan tool may be needed if active regeneration is repeatedly interrupted.