Diesel engine automotive emissions gases include diesel particulates that are harmful to the human body, including carbon-monoxide (CO), Hydrocarbons, Nitrogen compounds and particulate matter (PM). In order to address these harmful components, regulations governing diesel engine automotive emission gases have become stricter. To comply with such regulations, improvements in engine performance and emission purification will be necessary. N.E. CHEMCAT, building on our technologies and experience in gasoline auto exhaust catalysts, are developing and manufacturing catalysts meeting these demands.