Exhaust emission control apparatus for internal combustion engine

摘要

There is provided an exhaust emission control apparatus for an internal combustion engine, which comprises a cylinder suspend operation control section that provides control to suspend combustion of suspended cylinders selected from among a plurality of cylinders according to an operating state of the internal combustion engine, a first exhaust passage connected to the suspended cylinders, a second exhaust passage connected to operating cylinders other than the suspended cylinders, a second exhaust purifying catalyst disposed in the second exhaust passage, and a first exhaust purifying catalyst disposed in the first exhaust passage and having a higher capability to purify exhaust gas than the second exhaust purifying catalyst. It is therefore possible to prevent deterioration of exhaust gas even in the case where cylinders are partially suspended.