P0456 2002 Nissan Sentra -

Question

My check engine light is on with P0456 code. I replaced the fuel cap bought from the dealer. The light came back on 3 days after installing the new cap. Should I just replace the canister to see if that's the problem?

Answer 1

Hi there,

What I would do is remove the vent control valve from the canister. Then run a power and ground wire to the pins on the valve and make sure it makes a clicking type of noise when you do this. You can also look inside it and see if it is rusty. A lot of times you will get this code because the vent control valve is stuck in an open position.