Patent ID: 8001769

Claim:
An emissions control system, comprising: a power source that creates a flow of exhaust; a filtering device that receives the flow of exhaust; a first sensor located at or upstream of the filtering device, the first sensor being configured to measure a first temperature; an SCR catalyst located downstream of the filtering device; an injector configured to inject a reduction agent into the flow of exhaust in the presence of the SCR catalyst; a second sensor located at or upstream of the SCR catalyst and downstream of the filtering device, wherein the second sensor measures a second temperature; and a controller in communication with the first sensor, the controller configured to: predict a change in an ability of the SCR catalyst to store reduction agent using a measured change in a characteristic temperature; and adjust the injector according to the predicted change in the storage ability of the SCR catalyst, wherein the controller uses the first temperature and the second temperature to calculate the characteristic temperature.