Patent ID: 8087232

Claim:
An exhaust system of an internal combustion engine having a plurality of cylinders, comprising: a first cylinder group and a second cylinder group which constitute all of the cylinders of the engine; a first exhaust passage and a second exhaust passage that are connected to respective exhaust manifolds of the first cylinder group and the second cylinder group, the first exhaust passage and the second exhaust passage having respective junction points through which the first and second exhaust passages communicate with each other; a turbine of a turbocharger disposed downstream of the junction point of the first exhaust passage; a first control valve disposed downstream of the junction point of the first exhaust passage; a second control valve disposed downstream of the junction point of the second exhaust passage; an HC adsorption device, having a first heat capacity, disposed in the first exhaust passage downstream of the turbine; an auxiliary catalytic converter, having a second heat capacity, disposed in the second exhaust passage upstream of the second control valve, the second heat capacity being lower than the first heat capacity; and a controller that controls opening amounts of the first control valve and the second control valve so that exhaust gas of all of the cylinders mainly passes the HC adsorption device during a period from cranking to a point in time immediately after completion of startup of the engine.