Well I'm on my second f-body a 98 t/a and it wasn't a week after buying the car it started making a pretty high pitched whistling noise I've been driving it this way for around 4 months no issues with stalling at all and its only every 2 or 3 minutes it becomes noticeable for around 10 seconds then all is quiet even sitting it does the same thing mpg seems to be a little on the low side around 16 mpg 60% city 40% highway with a pretty light foot. Is this possible fuel system related problem or could it be narrowed down to a vacuum leak? car only has a Borla catback