Fuel Vapor Rollover Valve - 626
WARNING: This page is about a different car, the 2001 Mazda Protege, 2001 Mazda Millenia, 2001 Mazda MX-5 Miata, 2001 Mazda MPV, and 2001 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.
Two fuel vapor rollover valves are located in top of fuel tank. Remove fuel vapor valve. It may be necessary to remove fuel tank to access valve. Hold valve in level upright position. Blow air into port (hose barb). Air should flow through valve to lower port. Turn valve upside down. Air should not flow through valve. Replace valve as necessary.