Yeah I thought it must be something to do with noise more than anything else, it sounds much better when its open (what I think is open anyway).
if you want you can disconnect the cable.
this makes the flapper stay open all the time.
to do this:
remove the seat.
take out the screws holding the flapper servo motor in.
lift it up.
MAKE A NOTE OF HOW THE WHEEL IS. put a mark on it with a sharpie if you have to.
turn it by hand so you get the cable off
with the cable off now off, TURN IT BACK SO IT IS WHERE IT WAS.
bolt it back on, and turn on the key..
if you get a FI light, you didnt put it back where it was.. it doesnt have to be perfect, but it should be close.
if theres no FI light, put the seat back on and you're done.