I am curious, do diesel engines use Evap Monitors like gasoline engines? If not why?No, they don't need to. It has to do with what is called Reid Vapor Pressure"RVP". This is an established method for measuring a fuel's volatility( the tendency of a liquid to evaporate under a given set of conditions). According to the EPA the least volatile blend of gasoline has a RVP of 7.4 psi at 100 degrees F. Diesel fuel No. 2 has an RVP of .022 psi at 100 degrees F, making evap emmisions a non-issue in diesel powered vehicles.
