The 4 State Trucks Blog

Let’s break down how to maintain peak emissions performance and avoid excessive repairs. In this guide we’ll cover the various Diesel Exhaust Fluid (DEF) and Diesel Particulate Filter (DPF) products and their functions, from gaskets and clamps to slipcovers. DPF and DEF systems aren’t related in any way. But they’re both critical aftertreatment systems for toxic exhaust emissions on a big rig.  Diesel Particulate Filters: The History, The Controversy Before 2003, th …