APPARATUS FOR CONTROLLING TRANSMISSION OF INTERNAL COMBUSTION ENGINE AND METHOD FOR DELAYING DETERIORATION OF EMISSION CONTROL CATALYST

摘要

In an emission control apparatus of an internal combustion engine in which an emission control catalyst is disposed in an engine exhaust passage, if fuel cut is performed during a decelerating operation of the engine when the temperature of the emission control catalyst is to be quickly reduced by a secondary air supply device supplying fresh air to the emission control catalyst during the decelerating operation of the engine, the supply of fresh air from the secondary air supply device to the emission control catalyst is started after a fuel cut executing condition is met but before the fuel cut is actually executed. Therefore, the temperature of the catalyst is reduced before the exhaust air-fuel ratio shifts to the lean side due to execution of the fuel cut. Thus, exposure of the catalyst to a deteriorating condition of high temperature and lean air-fuel ratio is prevented.