A method and related apparatuses and systems for operating an engine that provides a high level of NOX to regenerate particulate matter deposited on a particulate filter. The method includes producing NOX in response to a NOX excess capacity value of a NOX reduction device. The method optionally includes determining that particulate matter exceeds an enhanced passive regeneration threshold amount before providing a high level of NOX. The method optionally includes producing a higher particulate emissions output value to warm the engine exhaust to bring an aftertreatment catalyst to an optimal operating temperature. The method can be implemented with a closed loop feedback controller, which may be configured to reduce particulate matter variation.