System and method to reduce fuel cut enrichment non-methane hydrocarbon emissions

A control system for an engine of a vehicle includes one or more oxygen (O2) sensors disposed proximate to a three-way catalytic converter (TWC) in an exhaust system of the vehicle, the one or more O2 sensors each being configured to measure an O2 level of exhaust gas produced by the engine, and a controller in signal communication with the one or more O2 sensors. The controller is programmed to detect a fuel shut-off (FSO) event where the engine ceases providing fuel to the engine, determine an accumulated gas flow through the TWC during the FSO event, determine the FSO event has ended, and initiate a fuel enrichment event for a predetermined duration where the engine is supplied with a fuel enrichment level having a rich fuel/air ratio. The fuel enrichment level and the predetermined duration are chosen to reduce non-methane hydrocarbon (NMHC) emissions while maintaining NOx emission control.