Exhaust purification device for intracylindrical injection-type spark-ignition internal combustion engine

摘要

When an internal combustion engine is in a cold state (S12), fuel is injected during compression stroke with burn air/fuel ratio controlled so as to produce a slight lean air/fuel mixture equivalent to or slightly leaner than a stoichiometric air/fuel mixture (compression S/L operation) (S14), and also exhaust gas flow is restrained (S16).