Patent ID: 7380547

Claim:
A control system for adjusting levels of emissions exiting an engine with a camshaft that is associated with an exhaust valve and a cam phaser that interfaces with the camshaft, comprising: a NOx sensor that generates a NOx signal in response to oxides of nitrogen (NOx) in an exhaust gas; and a control module that communicates with the cam phaser, that receives said NOx signal, that calculates a NOx level of said exhaust gas based on said NOx signal, that compares said NOx level to a predetermined threshold range, that adjusts the cam phaser to achieve a rotational position that releases a desired level of NOx from the engine when said NOx level exceeds said predetermined threshold range, and that stores a rotational position value based on said rotational position in a storage device when said NOx level is within said predetermined threshold range, wherein said rotational position of the cam phaser controls an actuation time when the camshaft opens the exhaust valve during rotation of the camshaft.