The blue one is the main tank vent and the yellow is the water drain.

 

I'm thinking about putting a pcv/or check valve.

It's open to let pressure out, but not suck anything back in, easiest and quickest to do.

 

^ does the gas cap let air in though? Otherwise your fuel pump may struggle to deliver fuel if it cannot bring air into the tank as the fuel depletes.

 

Gas venting to atmosphere under the car seems kind of dangerous. I'm always smoking while working on it KA BOOOM!

 

I don't think the gas cap does to my knowledge. On my 99 Si I removed all this too, but I asked here b/c it's more involved than on my civic. Alot of extra b.s.

I was thinking of taking the smaller line and running it back up into the fuel door for venting.

 

Im pretty sure there is a smaller hard line that runs to the fuel door area. No idea what its for and I'm not at home to check but I seem to remember seeing a small line running along with the main filler hose...

 

There are 2 hard lines coming off the filler neck, you can see if you pop the trunk and move the divider out of the way. I'm not sure what's going on under the rubber boot where the filler connects to the tank.

 

Any updates on this Adam? I was looking at the 2 vacuum lines that T to the solenoid today and really want to rip them off and at least cap that hard line down below.

 

Its funny seeing this I just spent about 5 hours putting mine back on

 

Im curious for a strait answer on complete removal as well....I dont want this crap lol