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Exhaust

What is a Diesel Particulate Filter (DPF)?

Traps soot from diesel exhaust so it doesn't reach the air.

REGENTEMP600°CSOOTY EXHAUSTDPF FILTERCLEAN EXHAUSTTraps soot in cells, then burns it off at ~600°C

Simplified animation — not to scale.

In plain English

Found on modern diesels, the DPF is a fine filter in the exhaust that catches soot particles. It periodically burns them off in a process called 'regeneration'.

A simple analogy

"A self-cleaning oven — gets hot enough to burn off the gunk inside."

How it works

Exhaust gas flows through tiny channels; soot sticks to the walls. When the filter is full, the engine raises exhaust temperatures to burn the soot to ash.

Signs of trouble

  • ⚠DPF warning light
  • ⚠Loss of power / limp mode
  • ⚠Strong smell of diesel
  • ⚠Frequent short journeys (filter can't regenerate)
Rough UK cost

£300 cleaning – £2,000+ replacement

Always get a written quote. Prices vary by car, region, and parts brand.

Heads up: Carautonomy is for general guidance only. If your car is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.

Keep exploring

Alternator
The on-board power station that keeps your battery topped up.
EGR Valve
A small valve that recycles exhaust gas to reduce emissions.
Starter Motor
The muscle that turns your engine over when you twist the key.

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A friendly note

Information here is general guidance, not a diagnosis. Always speak to a qualified mechanic before parting with cash.

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