METHODS AND SYSTEMS FOR CONTROLLING SELECTIVE CATALYTIC REDUCTANT CATALYST OF A GASOLINE ENGINE

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NHthat is stored in a SCR. The amount of NHthat is stored in the SCR is a basis for generating additional NHor ceasing generation of NH.