| 摘要 |
A control device for a multicylinder spark-ignition engine includes a flow path switching unit for switching intake and exhaust flow paths between a two-cylinder interconnect configuration and an independent cylinder configuration and an air-fuel ratio control unit. In a low-load, low-speed operating range, the flow path switching unit switches the engine to the two-cylinder interconnect configuration, and the air-fuel ratio control unit produces a lean mixture having an air-fuel ratio larger than the stoichiometric air-fuel ratio by a specific amount in preceding cylinders by injecting fuel thereinto and an air-fuel ratio approximately equal to the stoichiometric air-fuel ratio in following cylinders by supplying fuel together with burned gas of a lean mixture state discharged from the preceding cylinders into the following cylinders to perform combustion in special operation mode. At engine startup, the flow path switching unit switches the engine to the independent cylinder configuration to perform combustion in normal operation mode.
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