Enhanced Evaporative Emission Control (EVAP) Systems Technical: Emission Specialist Module 1/4   This course will provide participants with a firm grasp of the function and operation of Evaporative Emission Control systems on today’s vehicles. Participants will also gain an understanding of Onboard Refuelling Vapour Recovery system operation as well as diagnostic techniques to employ when faced with malfunctions related to EVAP and ORVR systems.