Pardon the hi-jack, but I've seen several questions now from people wondering whether or not their cap should be vented or not.
It begs the question: what happens if you should be using a vented cap, but aren't? Aside from "suction when you remove the cap", does it cause other problems? Could it cause starting problems (perhaps because the gas is "vacuumed" back into the tank)?
If you need one and arent...you can encounter problems , like blowing your sending unit gasket if you park the car with full tank in hot weather , gas expands.
