Q: there is a bad canistor close valve. is that needed, does it have to be fixed to be a safe car

Hello. It may be that the technician possibly was referring to a canister purge valve or solenoid. If this was the case, then yes, it’s important to fix this for multiple reasons. First, the canister purge valve is responsible for relieving pressure inside your fuel tank. If the pressure isn’t relieved, it can cause the vehicle to stall or excessive, potentially harmful gases to seep from the fuel cell and harm vehicle occupants. Anytime a Check Engine Light is illuminated it means one of the parts on your vehicle needs to be serviced and should not be ignored. If you need help, a technician from YourMechanic can come to your home or office to inspect why the Check Engine Light is on and make the necessary repairs.