That small hose is the vent from the tank up to the filler. Sounds like you removed the hose, and plugged the nipple at the tank, and so it now has no vent. You might need a vented gas cap. Or redo the stock/original hose vent set up.

Tom

"Everyone should believe in something; I believe I'll go fishing."

-Henry David Thoreau

Men and fish are alike. They both get into trouble when they open their mouths

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