Process for testing the operating efficiency of exhaust gas catalysts

摘要

For testing the conversion rate of exhaust gas catalysts inserted in an exhaust gas train of an internal-combustion engine, a process is provided which first requires a first operating condition during a time period while specified marginal requirements are met. If these requirements are met, an exhaust gas pulse is generated during a second time period, for example, during a coasting operation, which exhaust gas pulse does not correspond to this condition. The reaction of a temperature sensor which is arranged downstream of the catalyst is then analyzed. If the change of the exhaust gas temperature because of the exhaust gas pulse is not within specified limits, a signal is triggered which indicates an unacceptably low conversion rate.