Systems and methods for idle fuel economy mode

A system comprising:

• an exhaust aftertreatment system including a reductant source and a selective catalytic reduction (SCR) component;
• and
• a controller in communication with the exhaust aftertreatment system, the controller structured to:
• determine an amount of stored reductant in the SCR component of the exhaust aftertreatment system;
• and
• control an amount of reductant added to the exhaust aftertreatment system during a standard engine idle mode of operation based on the amount of stored reductant, wherein the fuel mode economy circuit is structured to enter a fuel efficient engine idle mode in which the fuel mode economy circuit is inhibited from adding reductant during the fuel efficient engine idle mode in response to determining that a temperate of the SCR component is above a temperature threshold and in response to determining that an amount of time that the engine is in at least one of the standard engine idle mode and the fuel efficient engine idle mode is less than a fuel efficient idle time threshold.

A method comprising:

• detecting a level of nitrogen oxide present in a flow of exhaust gas downstream of a catalyst during an engine idle mode of operation;
• comparing the detected level of nitrogen oxide to a threshold;
• providing, during a standard engine idle mode, reductant to the catalyst in response to determining that the nitrogen oxide level is above the threshold;
• inhibiting, during a fuel efficient engine idle mode, reductant from being added during the fuel efficient engine idle mode in response to determining that a temperate of a selective catalytic reduction (SCR) component is above a temperature threshold and in response to determining that an amount of time that the engine has been in at least one of the standard engine idle mode and the fuel efficient engine idle mode is less than a fuel efficient idle time threshold.