Have had the tunes for about a month now. Noticed recently that there is a hissing sound like an air line leaking coming from somewhere on the vehicle. Thought maybe the pipe had come loose at the exhaust but can't seem to pinpoint it there. While at idle it is usually hissing and then can stop for a good few seconds before immediatley returning. It is always present when in motion. Any ideas? Also, a whining sound can occur during spool up, and is more evident with the 75 vs. the race tunes. These are more sporadic and seem to be during acceleration and are more noticeable during humid weather.