Abstract: An engine emissions control system may include an electronic control module and a nitrogen oxide sensor in communication with the electronic control module. The nitrogen oxide sensor may be mounted on an exhaust system of an engine and may be configured to provide the electronic control module with feedback indicative of an actual level of nitrogen oxide in an exhaust stream flowing through the exhaust system. The engine emissions control system may also include an engine parameter adjustment assembly controlled by the electronic control module. The electronic control module may automatically actuate the engine parameter adjustment assembly to adjust an engine flow until the actual level of nitrogen oxide reaches a desired level of nitrogen oxide.

Abstract: An engine emissions control system is provided. The system may include an exhaust producing engine and an exhaust system through which the exhaust produced by the engine may flow. The system may also include a NOx sensor configured to take a NOx measurement of the amount of NOx in the exhaust produced by the engine. The system may further include a charge density sensing system configured to measure the charge density of a combustion mixture of the engine. In addition, the system may include a controller configured to receive information related to the measurement of the amount of NOx. The controller may be further configured to control a charge density of the combustion mixture with which the engine operates based on the NOx measurement and the charge density measured by the charge density sensing system.