| CPC F02D 41/0255 (2013.01) [F02D 41/0007 (2013.01); F02D 41/0055 (2013.01); F02D 2200/08 (2013.01)] | 18 Claims | 

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               1. An intake and exhaust system comprising: 
            an engine; 
                an exhaust flow passage coupled to the engine; 
                a catalyst disposed in the exhaust flow passage and configured to purify exhaust gas; and 
                a control apparatus comprising 
                one or more processors, and 
                  one or more memories coupled to the one or more processors, wherein 
                the one or more processors are configured to 
                before the engine is started up, execute scavenging control that causes 
                  the exhaust gas remaining in the engine and the exhaust flow passage to flow to pass through the catalyst before being discharged, and 
                    identify a degree of purification of the exhaust gas by the catalyst, and 
                  before the engine is started up, execute warming control that warms up the catalyst, based on the identified degree of purification of the exhaust gas by the catalyst during execution of the scavenging control, 
                the intake and exhaust system further comprising 
                an on-off valve disposed in the exhaust flow passage, and 
                  a throttle valve disposed in an intake flow passage coupled to the engine, wherein 
                the one or more processors are configured to 
              after the engine is stopped, close the on-off valve and the throttle valve to cause the exhaust gas to stay in the engine and the exhaust flow passage, to increase an amount of the exhaust gas to flow to pass through the catalyst during the scavenging control. 
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