METHOD OF MONITORING THE EXHAUST CATALYST OF AN INTERNAL COMBUSTION ENGINE

摘要

The aim of the invention is to provide a method for monitoring an exhaust catalyst (17) while the internal combustion engine (10) is still warm from operation. To this end, an NOx sensor (19) is inserted downstream of the exhaust catalyst (17) to be analyzed to determine the NOx concentration (c_NOx). During the diagnosis interval the oxygen charge of the exhaust catalyst (17) is increased. The NOx concentration (c_NOx) measured during several lambda control oscillations is used to draw conclusions regarding the conversion property of the exhaust catalyst (17).