Re: code pointing towards evaporative canister
There is a hose that is attached to the intake manifold which then goes to a solenoid by left valve cover
From there is a black flex hose that goes back toward firewall and then to canister.
I believe if not moved since the C5 is in the right rear of car.
Make sure the hoses in engine bay are connected, not broke and wiring connector on solenoid.
Best is with a good OBD scanner that has bi-directional control as EVAP could be sent a command and via scanner see if solenoid changes state.
Many times people do not turn the gas cap enough to the right to assure cap is sealed
Mike M - 2001 / 2008 Z06s