FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: proposed device is designed for monitoring catalytic activity of converter 1 in exhaust system of internal combustion engine 3. Controlled temperature parameter is formed by signals of at least two temperature pickups 4, 5, 6 installed in converter 1. Temperature pickups are monitored during sufficient time period to find averaged value with due account of various operating conditions of internal combustion engine 3 or with due account of other measured parameters which are obtained from engine observation system 7 and are characteristic of operating condition of engine 3. They are used to evaluate the condition irrespective to current condition of engine and then are compared with preset value. If measured temperature parameter is lower that preset value, signal is initiated to indicate trouble in catalytic converter. EFFECT: enhanced reliability of operation. 14 cl, 7 dwg
