EVAP stands for Evaporative Emission Control System.
It is mainly associated with petrol vehicles.
Fuel naturally produces vapors inside the fuel tank. The EVAP system stores these vapors and later
routes them into the engine so they can be burned instead of being released directly into the
atmosphere.
A faulty purge valve, leak or related sensor can trigger EVAP fault codes.
This module is therefore much more commonly encountered on petrol vehicles.