摘要 |
An exhaust control system has a first catalytic device disposed in an exhaust line and a second catalytic device, which is smaller in capacity than the first catalytic device, disposed in the exhaust line upstream from the first catalytic device. The system includes a shutter device disposed in the exhaust line upstream from the first catalytic device. The shutter device is caused, by a controller, to close the exhaust line during a predetermined period from a start of engine cranking, before an engine is warmed up, and open the exhaust line after the engine is warmed up, thereby promoting activation of the catalytic devices. |