US Patent 7469667 Method for controlling a variable event valvetrain

A method for controlling a variable event valvetrain during engine start and stop is presented. According to the method, valve lift and/or timing can be adjusted to reduce the amount of oxygen pumped into an exhaust gas after treatment system. The method can reduce engine emissions, at least during some conditions, since there may be less oxygen available to alter the operating state of the exhaust gas after treatment system.