Automobile exhaust purifying system

摘要

An exhaust purifying system for an automobile engine including an exhaust system for the emission of exhaust gases to the atmosphere through a catalytic converter. The system comprises a temperature detector for detecting a signal indicative of the temperature of the catalyst, a total engine operating hour detector for detecting a signal indicative of the total operating hour over which the engine has been operated, a spark timing control for retarding the spark timing when the temperature detector detects that the catalyst temperature is lower than a predetermined value, and a retard time corrector for increasing the amount of control to be performed by the spark timing control with increase within a predetermined range detected by the total engine operating hour detector.