1. Remove the evaporative gas check valve (one-way).
2. Apply pressure to port A, and verify that there is no airflow.
3. Apply negative pressure to port A, and verify that there is air flow.

Charcoal canister inspection
Purge solenoid valve removal/installationMazda 6 Service Manual: Foreword
When the customer reports a vehicle malfunction, check the malfunction
indicator lamp (MIL) indication and diagnostic trouble code (DTC), then
diagnose the malfunction according to following flowchart.
- If a DTC exists, diagnose the applicable DTC inspection. (See DTC
TABLE.)
- ...
Mazda 6 Service Manual: Fuel-Filler Cap
To remove the fuel-filler cap, turn it counterclockwise.
Attach the removed cap to the inner side of the fuel lid.
To close the fuel-filler cap, turn it clockwise until a click is heard.
CAUTION
(U.S.A. and Canada) If the check fuel cap warning light illuminates,
the fuel-filler cap may not ...