Patent ID: 6321529
Filing Date: 2001-11-27
Classification: F01N,F02D

Abstract:
An exhaust system of a multi-cylinder internal-combustion engine consisting of at least one system part in which the internal-combustion engine exhaust gases or portions thereof are first guided through at least two partial pipe trains apportioned to cylinder groups, one starting catalyst respectively being inserted in each of the partial pipe trains, said partial pipe trains combining to form a joint main pipe in which a main catalyst is inserted, a lambda probe being arranged in front of each of the respective starting catalysts and a lambda probe being arranged behind the main catalyst,wherein, in the case of n partial pipe trains, only n-1 additional lambda probes are provided upstream in the partial pipe trains of the main catalyst and upstream of the joint main pipe,wherein means are provided for measuring an air/fuel ratio and generating a first air/fuel ratio signal using a first lambda probe disposed upstream of a first starting catalyst, in a first one of said partial pipe trains,wherein means are provided for measuring an air/fuel ratio and generating a second air/fuel ratio signal using a second lambda probe disposed upstream of a second starting catalyst in a second one of said partial pipe trains,wherein means are provided for measuring an air/fuel ratio and generating a third air/fuel ratio signal using a third lambda probe disposed in said first one of said partial pipe trains downstream of the first lambda probe, andwherein means are provided for controlling operation of said engine as a function of said first, second and third air/fuel ratio signals to thereby minimize pollutants in engine exhaust gases flowing through the partial pipe trains and the joint main pipe.