Technician A says that fuel filler caps with pressure and vacuum vents are used with EVAP system fuel tanks. Technician B says that using a non-vented cap on a system equipped with an evaporative emissions system may cause damage to the fuel tank. Which technician is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A is correct in stating that fuel filler caps with pressure and vacuum vents are used with EVAP system fuel tanks to manage the pressure and prevent fuel vapors from escaping into the atmosphere. Technician B is correct in stating that using a non-vented cap on a system equipped with an evaporative emissions system may cause damage to the fuel tank due to the buildup of pressure or vacuum, which the system is designed to regulate.

Technician a Says That Fuel Filler Caps with Pressure and Vacuum