Deceleration fuel shutoff mode for direct injection spark ignition engine

摘要

The supply control method involves the steps of determining an engine (10) operating condition, ceasing continuous fuel supply when a deceleration condition is detected, determining the amount of oxygen stored in the catalyst (37) and intermittently supplying fuel to the engine, for a number of engine cycles, based on the amount of oxygen stored in the catalyst, to produce a rich air-fuel mixture. Determining the amount of oxygen stored in the catalyst is based on the air flow rate through the engine, the engine speed and the temperature of the catalyst. Independent claims are included for a system of controlling the oxides of nitrogen emissions from a direct injection spark engine during deceleration and an electronically programmable chip and program code for utilizing the method.