This brand-new DEF Doser (Part #2888173) is a high-quality replacement designed for Cummins aftertreatment systems. It accurately meters Diesel Exhaust Fluid (DEF) into the exhaust stream to support proper SCR function, reduce NOx emissions, and maintain engine efficiency. Perfect replacement for worn, clogged, or malfunctioning DEF dosers commonly found on late-model Cummins engines. Direct Replacement for Cummins 2888173. Ensures Proper DEF Atomization for optimal SCR performance. Reduces Emissions & Prevents Fault Codes. Restores Exhaust Aftertreatment Efficiency. Simple Installation – Plug-and-Play Fitment.