P1451 is a fault in the solenoid circuit for the evaporator canister vent. It's probably stuck open. I'm afraid I've never replaced one before, so I don't know what it entails. Hopefully others can fill you in.
I would just clear the other codes and run the car for another few hundred miles and see if any reappear. If the alternator code re-appears, you may have a faulty wiring harness connecting to the alternator, or the alternator itself needs to be tested.