Hello, I had a p0449 code and replaced the purge valve solenoid and then I got a p0455 code. I replaced the gas cap and the canister vent valve but still have the p0455 code. I did a smoke test but system seems sealed . The electrical connectors have power to them and are in good shape. What else could be the culprit? Could the fuel tank pressure senor be throwing the p0455 code? Thanks for any help.