1. Remove the charcoal canister.
2. Plug the atmosphere side port and purge solenoid valve side port of the charcoal canister.
3. Blow air into the charcoal canister from the fuel tank side port and verify that there is no air leakage.

Emission system
Evaporative gas check valve (one-way) inspection (l.h.d.)Mazda 6 Service Manual: Oil leakage inspection
Use either of the following procedures to identify the type of oil that
is leaking:
Using UV Light (Black Light)
1. Remove on the engine or transaxle.
Note
Referring to the fluorescent dye instruction manual, mix the
specified amount of dye into the engine oil or ATF (or transaxle ...
Mazda 6 Service Manual: Variable air duct (vad) control solenoid valve inspection (l3)
1. Remove the VAD control solenoid valve. (See INTAKE-AIR SYSTEM
REMOVAL/INSTALLATION.)
2. Inspect airflow between the ports under the following conditions.
If not as specified, replace the VAD control solenoid valve.
If as specified, carry out the Circuit Open/Short Inspection.
Circ ...