Hello guys, this has probably come up a million times but my 2005 silverado 1500 with the 5.3L has a p0446 EVAP code. Its for a vent control circuit malfunction. I have done a ton of research and have replaced a few parts so far including the vent valve, fuel cap, and fuel tank pressure sensor. WHAT else can it be!! The only symptoms I notice that could be a clue is every now and then when I begin fuelling, the pump stops like 4 or 5 times and then pumps steady to fill up. Could this be a sign of a bad canister? I'm not sure if anyone has any idea let me know, I got to pass emissions in February. Thanks!