2006 Nissan Pathfinder — Repair Manual - Emission Control System (Section EC)
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire. When a stick is inserted, the valve should open, when removing stick it should close. Connect a spare fuel hose, one side to fuel gauge retainer where the hose was removed and the other side to a fuel container.
In this process the air passes through the hose connecting air inlet tubes to rocker cover. Under full-throttle condition, the manifold vacuum is insufficient to draw the blow-by flow through the valve. On vehicles with an excessively high blow-by, the valve does not meet the requirement.
A strong vacuum should be felt immediately when a finger is placed over valve inlet. These items are required by legal regulations to continuously monitor the system/ component. Each diagnosis may require a long period of actual driving under various conditions.