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: Dtc c1955, c1956
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...
Mazda 6 Service Manual: Replacing a Wheel
WARNING
Always use wheels of the correct size on your vehicle: Using a wrong-sized
wheel is dangerous. Braking and handling could be affected, leading to loss of control
and an accident.
CAUTION
A wrong-sized wheel may adversely affect:
Tire fit
Wheel and bearing life
Ground clearance ...