Systems and methods for measuring exhaust gas species and SCR catalyst NOx storage for SCR-related controls and diagnostics

Abstract

A system includes a controller for an exhaust aftertreatment system including a SCR catalyst in exhaust gas-receiving communication with an engine and at least one reductant dosing system structured to provide reductant to the exhaust gas. The controller is structured to determine a ratio of NO to NO2 at or proximate an inlet of the SCR catalyst. The controller is further structured to command the at least one reductant dosing system to increase, decrease, or maintain an amount of reductant provided to the exhaust gas based on comparing the ratio of NO to NO2 to a previous NO to NO2 ratio.

Dependencies are inferred from the claim text.