CATALYST MONITORING SYSTEM AND CATALYST MONITORING METHOD

摘要

The concentration of a portion of components in the hydrocarbon in exhaust gas flowing into a catalyst (11) is detected or estimated, and the concentration of the portion of components in the hydrocarbon in the exhaust gas flowing out of the catalyst (11) is detected. On the basis of the concentrations of the portion of components in the hydrocarbon flowing into the catalyst (11) and the concentration of the portion of components in the hydrocarbon flowing out of the catalyst (11), it is determined whether or not the catalyst (11) has been deteriorated.