Difference Between a Catalytic Converter and a DPF Filter

A catalytic converter and a DPF filter are both part of the exhaust system and can look similar from the outside. They have different purposes and construction, and we buy both.

	Catalytic converter	DPF filter
Purpose	Chemically converts harmful gases (CO, hydrocarbons, nitrogen oxides) into less harmful ones	Traps soot particles from the exhaust gases
Vehicles	Petrol and diesel vehicles	Mainly diesel vehicles
Core	Flow-through honeycomb — gas passes through open channels	Filter block — channels alternately closed, gas passes through the walls
Precious metals	Platinum, palladium, rhodium in the catalytic coating	Many DPFs have a catalytic coating or are combined with a catalytic converter
Buyback	Valuation by serial number or photo	Valuation by marking, photo and vehicle details

How to tell which part you have

• Look at the front face of the core if it is visible: on a DPF filter the channels look like a checkerboard (every other one is closed).
• A DPF is usually closer to the middle of a diesel vehicle's exhaust system and often has connections for pressure sensors.
• If you are not sure — send a photo and the markings. We value both parts.

More: what is inside a catalytic converter · what is a DPF filter.