Not sure if this has been covered previously?
The previous owner decided to cut the return line for the charcoal canister in my car. I discovered this, and rather than attempt to reconnect it, I simply removed the whole system, capping any lines that were connected to it.
The car has a problem, though. The gas tank develops vacuum when the gas cap is sealed. I tried a vented gas cap, but still no joy. Whenever I open the gas cap, it sucks in a significant quantity of air. I fear that eventually it will develop enough vacuum to overload the fuel pump or collapse the tank. My solution thus far has been to not fully tighten the cap, but does anyone have a better solution?
(My county doesn't require smog checks)