What happens during DPF regeneration?

DPF Removal | What Is The DPF Regeneration Process? [TECH TALK] Contrary to popular belief, removing your DPF or CAT might not net you any performance gains. As emissions become more important, particularly in the US market, legally modifying your vehicle is becoming more difficult. This means manufacturers have worked hard to improve diesel particulate filters (DPF) and catalytic converters (CAT) to the point that in many late model vehicles their removal alone will not give you any performance