Patent ID: 7080511
Filing Date: 2006-07-25
Classification: F01N,F02B,F02D,F02M,Y02T

Abstract:
1. A method for controlling engine air/fuel ratio wherein an engine includes a plurality of cylinders fed by fuel injectors, an intake, and an exhaust, a compressor has an inlet receiving air, the compressor discharging air to the engine intake, the method comprising: providing a recirculation path extending from the compressor discharge to the compressor inlet, wherein a controllable valve is located along the recirculation path; controlling the valve to vary the air flow to the engine intake, thereby controlling the air/fuel ratio; wherein a lean NOx trap receives the engine exhaust, the lean NOx trap requiring a rich fuel mixture for regeneration; and periodically regenerating the lean NOx trap by controlling the valve to reduce the air/fuel ratio.