A method comprising: operating a system including an internal combustion engine to produce an exhaust gas flow through an aftertreatment system, the aftertreatment system including at least one selective catalytic reduction catalyst, an exhaust throttle upstream of the SCR catalyst, and wherein the aftertreatment system is configured such that the exhaust gas flow is not filtered for particulates upstream of the SCR catalyst; determining at least one parameter associated with operation of the system that indicates a contamination condition of the SCR catalyst, wherein the contamination condition is caused at least in part by accumulation of contaminants on the SCR catalyst; determining that a temperature condition associated with the SCR catalyst is less than a first predetermined threshold; in response to the contamination condition, initiating a thermal management event to at least partially remove the contaminants from the SCR catalyst by increasing a temperature of the exhaust gas flow to a contaminant removal temperature range, wherein initiating the thermal management event includes closing the exhaust throttle in response to the temperature condition of the SCR catalyst being less than the first predetermined threshold; operating the internal combustion engine to increase a thermal output of the internal combustion engine during the thermal management event to produce exhaust gas flow in the contaminant removal temperature range for a period of time to remove the contaminants; and counting a time of a previous thermal management event for the SCR catalyst to lessen a duration of the period of time of the thermal management event based on a type of the previous thermal management event occurring in the contaminant removal temperature range for the thermal management event. operating a system including an internal combustion engine to produce an exhaust gas flow through an aftertreatment system, the aftertreatment system including at least one selective catalytic reduction catalyst, an exhaust throttle upstream of the SCR catalyst, and wherein the aftertreatment system is configured such that the exhaust gas flow is not filtered for particulates upstream of the SCR catalyst; determining at least one parameter associated with operation of the system that indicates a contamination condition of the SCR catalyst, wherein the contamination condition is caused at least in part by accumulation of contaminants on the SCR catalyst; determining that a temperature condition associated with the SCR catalyst is less than a first predetermined threshold; in response to the contamination condition, initiating a thermal management event to at least partially remove the contaminants from the SCR catalyst by increasing a temperature of the exhaust gas flow to a contaminant removal temperature range, wherein initiating the thermal management event includes closing the exhaust throttle in response to the temperature condition of the SCR catalyst being less than the first predetermined threshold; operating the internal combustion engine to increase a thermal output of the internal combustion engine during the thermal management event to produce exhaust gas flow in the contaminant removal temperature range for a period of time to remove the contaminants; and counting a time of a previous thermal management event for the SCR catalyst to lessen a duration of the period of time of the thermal management event based on a type of the previous thermal management event occurring in the contaminant removal temperature range for the thermal management event.