METHOD AND SYSTEM FOR ENGINE CONTROL

Methods and systems are provided for improving fuel efficiency, monitor completion, and tailpipe emissions of a variable displacement engine. Fueling is initially disabled in cylinders selected to be deactivated while pumping air through the cylinders to an exhaust after-treatment catalyst and oxygen sensor. Once the sensor shows a lean response and catalyst monitoring is completed, cylinder valve operation is also disabled to reduce pumping losses and prevent further oxygen saturation of exhaust components.