摘要 |
Exemplary methods, devices, and/or systems are suitable for regenerating a plurality of after-treatment units. An exemplary method includes selecting less than all of a plurality of after-treatment units and adjusting air to fuel ratio for less than all of a plurality of combustion chambers of an engine to thereby cause the selected after-treatment units to receive exhaust having hydrocarbon and oxygen concentrations that favor regeneration of the selected after-treatment units. Other exemplary methods, devices and/or systems are also disclosed. |