First let's talk about what your EVAP system is, why car manufacturers introduced it, what it does and how it works... What is an EVAP system? EVAP is the automotive industry abbreviation for evaporative emissions systems. Designed to control the release of raw fuel vapour into the atmosphere. In the past before emissions laws started playing a major role in how cars and trucks are manufactured, excess fuel vapour in your fuel tank would have just been vented into the air. In