kikkegek, if ya keep removing stuff, you might actually save a little mpg from not having to carry around that extra weight.
benoit454, that exactly what mine is doing. If that vent line that ran to the canister was working as I thought it was supposed to, it shouldn't build up any pressure at all, kind of curious to whats going on there myself. I'd almost swear I get worse mpg if I let it build up for awhile, but that could all be in my head.
Picked up another fuel cap that I had laying around here, its the plastic type like is in my truck, I thought I was going to switch it out to test, but the vent in this cap doesn't work well either, and its supposed to be a vented cap, takes a fair amount of pressure to get any air through it.
Sorry to kind of wander off topic.