The EGR (Exhaust Gas Recirculation) system on your 2013-2024 Cummins pulls exhaust at various intervals / cycles and recycles it back into the engine via a valve on the intake manifold.
This valve can become contaminated with soot and lose its functionality, causing the engine to perform improperly and throw check engine lights. It is a critical part of your emissions system, and for states that test for emissions, could result in a fail if it is not functioning correctly. If your EGR valve is in need of replacing, or if you're previously removed it and looking to reinstall, this is a direct stock replacement.