Patent ID: 6978603

Claim:
An exhaust gas control method for an internal combustion engine including an exhaust gas control device, provided in an exhaust passage of the internal combustion engine, that oxidizes particulate matter produced in conjunction with combustion of gasoline in a combustion chamber of the internal combustion engine, the method comprising the step of: changing between first air-fuel ratio control that performs a feedback control toward a stoichiometric air-fuel ratio whereby an amount of oxygen in exhaust gas is reduced and second air-fuel ratio control that performs a feedback control toward a lean-burn combustion side whereby the amount of oxygen in exhaust gas is increased, wherein the first air-fuel ratio control normally performs the feedback control toward the stoichiometric air-fuel ratio and a change to the second air-fuel ratio control is performed if a predetermined condition relative to a state of particulate matter in the exhaust gas control device is met.