Methods and systems for engine exhaust catalyst operations

A method for an engine in a hybrid vehicle, comprising:

• in response to an upcoming engine start during a cold-start condition,
• opening an exhaust gas recirculation (EGR) valve coupled to an EGR passage to establish fluidic communication between an intake passage and an exhaust passage;
• activating an electric compressor and/or an air pump coupled to the intake passage;
• routing compressed air from the intake passage to an exhaust catalyst housed in the exhaust passages;
• closing an intake throttle positioned between the EGR valve and an intake manifold while adjusting an opening of the EGR valve to increase energy of pressurized air routed to the exhaust passage;
• and
• maintaining the engine inactive until attainment of light-off of the exhaust catalyst.

A system for an engine, comprising:

• an exhaust catalyst coupled to an exhaust passage;
• an exhaust gas recirculation (EGR) passage coupling an intake passage to the exhaust passage upstream of the exhaust catalyst;
• and
• a controller including executable instructions stored in a non-transitory memory that cause the controller to:
• in response to anticipation of an upcoming engine start, initiating warmup of the exhaust catalyst by routing compressed air through the exhaust catalyst via the EGR passage, closing an intake throttle positioned between an EGR valve and an intake manifold while adjusting an opening of the EGR valve to increase energy of pressurized air routed to the exhaust passage, and delaying the engine start until a temperature of the catalyst increases to above a threshold temperature.