Engine controller and method for controlling engine

An engine controller applied to an engine, wherein the engine includes a turbine arranged in an exhaust passage, a bypass passage branched from the exhaust passage at an upstream side of the turbine in the exhaust passage and joined with the exhaust passage at a downstream side of the turbine in the exhaust passage, a wastegate valve arranged at a joining location of the bypass passage and the exhaust passage, and a catalyst device for purifying exhaust gas arranged at a downstream side of the joining location in the exhaust passage, the engine controller being configured to execute a catalyst accelerated activation control that maintains the wastegate valve in an open state and accelerates activation of the catalyst device when the engine is started in a cold state, the engine controller comprising:

• processing circuitry configured to execute the catalyst accelerated activation control by performing a first process that maintains an open degree of the wastegate valve at a specified first open degree and then performing a second process that changes the open degree of the wastegate valve to an open degree that differs from the first open degree.