Hello , I can't help you with your Question.. but I have a TaoTao Quantum also
got it in March 2021. Nice to see another owner Forum member with one here. Mine also has that hose attached to the Air Box hose. What it is for I don't know. But for it to be attached to the air box hose like that.. I guess the Chinese wanted that little hose to have some filtration of clean air going through that hose.. so dirty air don't get sucked into wherever it leads to.