Catalyst protection during misfire

A method of performing a catalyst protection operation during a cylinder misfire event for a vehicle having an internal combustion engine having at least one cylinder bank, and an exhaust system having a catalyst, the method comprising:

• monitoring and counting, by a controller, a number of cylinder misfires on each cylinder bank;
• determining, by the controller, if the cylinder misfire count exceeds a predetermined threshold count that is below a maximum misfire count where the controller is configured to set an engine misfire fault;
• and
• in response to the cylinder misfire count exceeding the predetermined threshold count and being below the maximum misfire count in a particular cylinder bank, subsequently, by the controller, (i) setting a reduced engine torque limit and (ii) operating the particular cylinder bank in a stoichiometric fuel/air ratio, to thereby facilitate preventing excessively high temperatures at the catalyst due to the cylinder misfire event.

A method of performing a catalyst protection operation during a cylinder misfire event for a vehicle having an internal combustion engine having at least one cylinder bank, and an exhaust system having a catalyst, the method comprising:

• monitoring and counting, by a controller, a number of cylinder misfires on each cylinder bank;
• determining, by the controller, if the cylinder misfire count exceeds a predetermined threshold count that is below a maximum misfire count where the controller is configured to set an engine misfire fault;
• and
• initiating a preemptive catalyst protection operation, in response to the cylinder misfire count exceeding the predetermined threshold count in a particular cylinder bank, the preemptive catalyst protection operation comprising:
• (i) setting, by the controller, a reduced engine torque limit based on a highest allowable torque to maintain the catalyst at or below a predetermined threshold temperature;
• and
• (ii) operating, by the controller, the particular cylinder bank in a stoichiometric fuel/air ratio, to thereby facilitate preventing excessively high temperatures at the catalyst due to the cylinder misfire event.