The Catalytic convertercat

Its role is to convert the poisonous exhaust gases from the engine into gases that are less harmful to the atmosphere. The nature of what they do and how they operate means they require maintenance and replacement from time to time.

This should always be diagnosed and attended to by a qualified technician, removing a catalytic converter from a system and not replacing it is illegal.

The removal of poisons is its role and when working properly it is very efficient.