A system according to the principles of the present disclosure includes a rate determination module, a storage level determination module, and an air/fuel ratio control module. The rate determination module determines an ammonia generation rate in a three-way catalyst based on a reaction efficiency and a reactant level. The storage level determination module determines an ammonia storage level in a selective catalytic reduction (SCR) catalyst positioned downstream from the three-way catalyst based on the ammonia generation rate. The air/fuel ratio control module controls an air/fuel ratio of an engine based on the ammonia storage level.
STATEMENT OF GOVERNMENT RIGHTS
This invention was produced pursuant to United States Government Program No. DE-EE0003379 with the Department of Energy (DoE). The U.S. Government has certain rights in this invention.