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: No. 2 all on-board diagnostic functions inoperative
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunctions. If there
is a problem, check to make sure connectors, terminals and wir ...
Mazda 6 Service Manual: Symptom troubleshooting
Verify the symptoms, and perform troubleshooting according to the
appropriate number.
Vehicles with ABS/TCS
Vehicles with DSC
*1 : DSC system contains traction control function, DSC indicator light goes
on and off while DSC operates.
*2 : DSC indicator light goes on and off while D ...