Abstract: Systems and methods determining a presence or absence of engine misfire at low engine load are disclosed. In one example, the presence or absence of engine misfire is based on a fuel target error value and an exhaust temperature error. Operation of an engine may be adjusted when engine misfire is detected.

Abstract: Methods and systems are provided for fueling an engine of a vehicle during an exit from a deceleration fuel shut-off (DFSO) condition. In one example, a method may include fueling the engine using a compression stroke direct injection during the exit from the DFSO condition to reach a first engine torque threshold, and may further include increasing a separation between the compression stroke direct injection and a spark to gradually increase the engine torque to a second, higher engine torque threshold, and thereafter transitioning engine fueling from the compression stroke direct injection to an intake stroke direct injection. In this way, torque bumps may be reduced during DFSO exit.

Abstract: Methods and systems are provided for fueling an engine of a vehicle during an exit from a deceleration fuel shut-off (DFSO) condition. In one example, a method may include fueling the engine using a compression stroke direct injection during the exit from the DFSO condition to reach a first engine torque threshold, and may further include increasing a separation between the compression stroke direct injection and a spark to gradually increase the engine torque to a second, higher engine torque threshold, and thereafter transitioning engine fueling from the compression stroke direct injection to an intake stroke direct injection. In this way, torque bumps may be reduced during DFSO exit.

Abstract: Embodiments for reactivating a catalyst are provided. In one example, a method for reactivating a catalyst coupled to an engine comprises when the engine is restarted following deactivation, adjusting a degree of fuel enrichment based on an engine off duration and an engine air amount during the restart.

Abstract: Embodiments for reactivating a catalyst are provided. In one example, a method for reactivating a catalyst coupled to an engine comprises when the engine is restarted following deactivation, adjusting a degree of fuel enrichment based on an engine off duration and an engine air amount during the restart.

Abstract: Embodiments for reactivating a catalyst are provided. In one example, a method for reactivating a catalyst coupled to an engine comprises when the engine is restarted following deactivation, adjusting a degree of fuel enrichment based on an engine off duration and an engine air amount during the restart.

Abstract: Embodiments for reactivating a catalyst are provided. In one example, a method for reactivating a catalyst coupled to an engine comprises when the engine is restarted following deactivation, adjusting a degree of fuel enrichment based on an engine off duration and an engine air amount during the restart.