Catalytic converter for a lean burn engine

摘要

A catalytic converter is described for a lean burn spark ignition internal combustion engine. The converter comprises a first and a second porous catalyst matrix 12, 14 connected in series with one another. The first matrix 12 has a coating that includes an oxygen storage material and the second matrix 14 has a coating that includes a NO x storage material. To allow rapid purging of the NO x trap, the catalytic converter includes a bypass to allow a proportion of the exhaust gases to flow to the second matrix 14 without that proportion loosing its HC and CO content by reacting with the oxygen stored in the coating of the first matrix 12.