In the Cat® Tier 4 Final engine, some NOx emissions are oxidized by the diesel oxidation catalyst. The engine reduces the amount of particulate matter that reaches your aftertreatment system. A diesel particulate filter traps particles that enter the exhaust stream. If soot builds up, the Active Cat Regeneration System activates to remove it. This all happens automatically without interrupting your work.
Always remember to refer to your machine's Operation and Maintenance Manual for more information. And reach out to your Cat dealer for any other questions about maintaining equipment.