US Patent 7874145 Emmision control device for internal combustion engine

Control is performed such that when an HC adsorption catalytic converter having an oxygen storage capacity is in a specified temperature range, fuel supply quantity is increased with a first increase ratio relative to basic fuel quantity based on the operating state of an internal combustion engine, in a first specified period after the end of fuel cut, and increased with a second increase ratio smaller than the first increase ratio, in a second specified period succeeding the first specified period.