A system includes a controller having at least one processor coupled to a memory storing instructions that, when executed by the at least one processor, causes the controller to: receive data indicative of operating conditions of at least one of an engine or of an aftertreatment system; determine, during a first period of time, that an amount of NOx output from the aftertreatment system satisfies a low NOx operating mode condition based on the data indicative of operating conditions; determine, during a second period of time, that operating conditions for a conversion efficiency are present based on the data indicative of the operating conditions of the aftertreatment system; determine that the amount of NOx output from the aftertreatment system satisfies a high NOx operating mode condition; and selectively set an alert based on a retrieved minimum value and a retrieved maximum value of the amount of NOx outputs.