So as i'm accelerating, around 5-6k my 03 f4i makes a hissing sound, might be around the cct. The only thought i have is that the gas i put in it was not the right octane, even though it said 93 or whatever premium is.(the place was being shut down and had a sale)

Also, over 160 degrees i hear a flicking/clicking sound. I can feel it on my right leg when i press up against the gas tank.


Any thoughts? i'm kinda stumped.