| 摘要 |
An exhaust system for a multi-cylinder internal combustion engine has at least two exhaust valves per cylinder. A first exhaust valve in each cylinder is connected to a first catalyst, and a second exhaust valve in each cylinder is connected to a second catalyst which opens out upstream of the first catalyst. The first exhaust valves or their outlets are kept closed during a starting phase of the engine, so that, during the starting phase, all the exhaust gases first pass through the second catalyst which is smaller than the first catalyst and is positioned closer than the latter to the engine. |
