Method for controlling and/or monitoring the performance of selective catalytic reduction
devices (SCR) and systems incorporating the same are provided. Systems can include a
SCR configured to receive reductant at a variable dosing rate, an upstream NOx sensor, and
a downstream NOx sensor. Methods can include correlating a SCR reductant dosing signal
direction with a SCR downstream NOx signal direction, and determining one or more of NOx
breakthrough through the SCR and reductant slip through the SCR. Methods can further …