Method for heating exhaust gas catalyser in internal combustion engine has first air/fuel mixture in first cylinder group richer than in normal running and with second air/fuel mixture in second cylinder group leads to catalyser heating

摘要

The method for the heating of an exhaust gas catalyser (10) in an internal combustion engine involves feeding a first air/fuel mixture into a first group of cylinders so that a positive engine torque can be build up, and feeding a second mixture into a second group of cylinders, whereby an inlet valve (11) and/or exhaust valve (12) are controlled in a way in which an engine braking torque is built up. The first air/fuel mixture in the first group of cylinders is richer than in normal running and together with the second air/fuel mixture in the second group of cylinders leads to heating of the exhaust gas catalyser.