large leak in the evaporation control system on 2004 BMW 330xi

that is what i have been told what is that? is it costly? also my hazard lights have been coming on for no reason and I have beeb unable to push the buton and turn them of. they keep doing this and now my battery is dead, because i was out of town this weekend and this morning it would not start. and my gas cap is on correctly

Asked by for the 2004 BMW 330xi
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