HELP!!!!

[Tonic]

Hey all

I seem to have put a small hole inone of the lines leading from the fuel cap to the fuel tank.

I cannot figure out what this line is before i replace it..

There seems to be TWO lines which come directly from the petrol cap(ie, where you put petrol in) to the fuel tank- obviously one is for the petrol line input but they are both cable tied together- both go from the petrol cap to the tank and are side by side. I seem to have a hole in the smaller of the pipes, can someone explain what this line is please, and what pipe should I use to replace it ? Is this just an overflow pipe or vapour pipe or something- it is a coiled plastic line which is made from very cheap stuff- whereas the other pipe which is intact is side by side all the way but is more durable and seems to be a rubber pipe with a coil plastic protection cover.

I assume it is an easy replace- just unhook at both ends?

Anyway before I ask a thousand questions, it would be great if someone could advise me of the role of this smaller pipe (smaller in diameter only, but same length as the input fuel line).

My tank is drained already while I mod the car, so I just would like to know what this line is for.

Thanks a abunch