Basic exhaust principles

When fuels are combusted, a number of harmless compounds such as water, carbon dioxide and nitrogen are produced, as well as a number of dangerous pollutants - such as carbon monoxide, nitrogen oxides and hydrocarbons.

Emissions emerge during the combustion of various fuel types which contain harmless and harmful components. It is necessary to reduce these harmful emissions, a task which is assumed by the catalytic converter. The limit values for the discharge of harmful emissions are defined in the so-called Euro standards.

In order to ensure optimal operating conditions of the catalytic converter, vehicles have at least one lambda sensor. This regulates the ideal mixture ratio of air and fuel. Only with the ideal mixture ("stoichiometric range") can the catalytic converter convert nearly all harmful emissions.

Related topics

The lambda control circuit: The engine control unit regulates ignition, the injection system and the idea air-fuel ratio.

The ideal mixture: This ideal mixture is identified by the Greek letter lambda.

Air ratio: The air ratio provides information about the mixture ratio.

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