A method and arrangement for maintaining an exhaust gas catalyst in an effective state

摘要

A method for maintaining a catalyst 702 of an emissions system 700 in a hybrid electric vehicle 10 in an operative condition is disclosed. The method includes sensing that an engine 511 of the hybrid electric vehicle 10 has stopped operating, predicting a time period after which the catalyst 702 will cool to a light-off temperature below which the catalyst 702 becomes ineffective and restarting the engine 511 when the predicted time period has expired thereby reheating the catalyst 702 above the light-off temperature.