Catalytic converters have a minutes long warm-up period beforce they approach a narrow interpretation of "effectiveness". Oh, and since we are talking about di

Catalytic converters have a minutes long warm-up period beforce they approach a narrow interpretation of "effectiveness". Oh, and since we are talking about diesels, they produce diesel particulate matter, ultrafine particles that can cause anything from cancer to nausea. Even modern diesel engines can't completely filter them.