US 12,228,090 B1
System and method to reduce fuel cut enrichment NOx emissions
Mark E Ives, LaSalle (CA); Kevin L Mason, Farmington Hills, MI (US); Justin Neufeld, Cottam (CA); Simon O Omekanda, Oakland Township, MI (US); and Muhammad Rizwan S Khan, Canton, MI (US)
Assigned to FCA US LLC, Auburn Hills, MI (US)
Filed by FCA US LLC, Auburn Hills, MI (US)
Filed on Dec. 1, 2023, as Appl. No. 18/526,002.
Int. Cl. F02D 43/04 (2006.01); F02D 41/24 (2006.01)
CPC F02D 43/04 (2013.01) [F02D 41/2422 (2013.01); F02D 2200/0614 (2013.01); F02D 2200/08 (2013.01); F02D 2250/36 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A control system for an engine of a vehicle, the control system comprising:
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 and 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;
initiate an open loop fuel enrichment mode where the engine is supplied with a first fuel enrichment level having a first rich fuel/air ratio; and
subsequently initiate a closed loop fuel enrichment mode where the engine is supplied with a second fuel enrichment level having a second rich fuel/air ratio, to thereby reduce NOx emissions,
wherein the first and second fuel enrichment levels are based on the determined accumulated gas flow through the TWC during the FSO event, and
wherein the controller is configured to transition from the open loop fuel enrichment mode to the closed loop fuel enrichment mode when (i) a voltage of the one or more O2 sensors exceeds a predetermined threshold voltage or (ii) an accumulated gas flow through the TWC during the open loop fuel enrichment mode has exceeded a predetermined flow threshold.