Engine control for limiting catalyst temperature in normal and economy modes

摘要

Systems and methods for operating an engine of a vehicle during high engine loads are presented. In one example, fuel may be conserved at higher driver demand torques by limiting engine torque when the engine is operated in an economy mode. Additionally, two accelerator pedal position based fuel enrichment schedules are provided for operating the engine in different operating modes.

主权项

1. A method for operating an engine, comprising:
advancing spark timing from a borderline spark timing toward minimum spark advance for best engine torque and enriching an engine air-fuel ratio in response to a catalyst temperature greater than a threshold temperature; and reducing engine torque in response to the catalyst temperature greater than the threshold temperature and selection of a fuel economy mode.