Diesel Exhaust Fluid is a critical component in a diesel truck's fuel system. Here's what it does and how much you can expect ...

A pump and the lines that carry the DEF to the exhaust system ... Availability: Although it's widely available at gas stations and truck stops, there may be a time when you find yourself on ...

The additive is, however, not added to diesel fuel before you pump it into your vehicle's gas tank, and is instead ... it can be easy to become confused and add DEF directly into the diesel ...