I have an '04 Silverado w/a 6.0L. and I have this code. I have replaced the purge valve and the vac. solenoid valve on the tank. I think this started as a P0440 code and later changed to the 446. I also noticed that the purge valve doesn't fit tight to the manifold, it is loose and wiggles even though the bolt is tight. Any thoughts or info for a fix?

 

No thoughts or ideas? Anybody

 

The solenoid on the manifold is designed to be loose after tightening the bolt. Did you change the filter when changing the purge valve by the tank. GM has a fix for the evap problems as the old design gets the filter to dirty and throws the evap code. The new fix places the filter on th top of the transmission. You should put a fuel cap on as any leak will throw these evap codes.