[captain awesome]

Originally Posted by Irace86.2.0

Not into it. Out of it. Dirt and moisture/water vapor can get into it.

Unless I am confused, the EVAP system purges gases from the gas tank. Evaporating gas would normally vent to atmosphere, which isn’t good, but just creating a closed system with an air-tight gas cap would cause pressure to build, especially in the heat, so that isn’t good either. This could be bad for seals, and it could cause pressure to rapidly escape when the gas cap is removed. The EVAP system filters and purges the pressure to the intake manifold to be burned.

I think if you remove everything and cap the system then that means you should burb the system or leave the gas cap off during storage for a long time, but regular and frequent fill-ups should relieve the pressure. If it is vented without the charcoal system then there may be odors and more emissions and potentially more opportunity for moisture and dirt to get in the tank. I don’t know how much of a risk there is in either way. I figured I would vent, but leave the particulates.

I think you are right. Honestly dropping the tanks doesn't sound like fun anyway.