Patent ID: 7757480

Claim:
An air-fuel ratio control apparatus of an internal combustion engine comprising: a plurality of exhaust gas purifying catalysts disposed in an exhaust gas purifying catalyst casing, the exhaust gas purifying catalyst casing disposed in an exhaust passage of the internal combustion engine; secondary air supplying means for supplying secondary air through a secondary air passage to at least one portion of the exhaust gas purifying catalyst casing, the portion of the exhaust gas purifying catalyst casing being disposed between the plurality of exhaust gas purifying catalysts; valve means for switching connection to or disconnection from the secondary air passage; valve controlling means for controlling operation of the valve means; and fuel cutting means for cutting fuel to be supplied to the internal combustion engine at the time of deceleration of the internal combustion engine, wherein the valve controlling means sets a supplying period, during which the secondary air is supplied by switching the valve means to a connection state during a non-operating period of the fuel cutting means after completion of a fuel quantity increasing operation of the internal combustion engine.