What are the symptoms of a faulty Mazda6 charcoal canister?

[Finn]

Mazda6 charcoal canister failure manifests through the following symptoms: 1. Difficult engine starting (charcoal canister solenoid valve stuck open): When the solenoid valve remains constantly open, the intake manifold becomes saturated with fuel vapors. This creates an excessively rich air-fuel mixture during engine startup, leading to hard starting or even stalling. 2. Fuel vapor leakage (charcoal canister solenoid valve stuck closed): A permanently closed solenoid valve prevents proper venting of stored fuel vapors, causing increased fuel tank pressure that eventually forces vapors to escape through the fuel cap pressure relief valve.