Exhaust Gas Recirculation System for Simultaneously Reducing NOx and Particulate Matter: 5,806,308

An exhaust gas recirculation system for internal combustion engines includes a particulate trap through which all of the gas exhausted through the exhaust manifold of the engine is cleaned prior to directing a first portion of the gas through a low pressure EGR loop and/or discharging all or a remaining portion of the exhaust gas to the surrounding environment. The EGR system embodying the present invention provides an efficient method for reducing NO.sub.x emissions by recirculation of a portion of the exhaust gas and, simultaneously, reducing particulate matter by passing all of the exhaust gas through a passive trap prior to recirculation or discharge to atmosphere.