Pontiac G5 getting P0455 code

Question

Getting the P0455 code on my pontiac g5 (2007 model). I've already replaced the gas cap and reset the codes which came back after driving on it for a couple of days. Just took it to a shop where they did smoke tests to check the hoses and came up with nothing. I am at a loss on what to do next, any ideas?

Answer 1

HI there

If the smoke test came back clean, then I would have the fuel tank pressure sensor tested. If it's not changing with the pressure on the tank, then it's possible the computer would see that as a gross evap leak and set the code. Also, make sure they checked the purge valve. If it's sticking open it would allow the smoke to go into the intake manifold and they won't see it with the smoke test.