hmmm thats very wierd, thankfully it hasnt happened to me (at least not yet haha) it could be a sensor in the fuel tank or a clogged fuel filter, as for the noise in the exhaust it could be a baffle in the muffler that has become loose, the same thing happened with my moms jeep wrangler, it would make a noise but only between 2500-2900 rpm then went away, kinda like clanking metal that dropped performance and hurt gas mileage a little bit, simple fix just bring it to the dealer. but if i were you i would take care of her with a whole new exhaust system, probably magnaflow but i found a nice borla one for around 700 bucks with a lifetime garuntee