I had another listen when I left work and couldn't hear the intermittent hiss when idling at all. I did hear it when I got home. I have a feeling it's just air/air pressure equalizing across the x pipe connection since that section seemed to be where it's coming from. Does that sound like a possibility? Anyways I'm not worrying too much. I don't have any cel lights or anything. On another note, this exhaust literally makes me smile when I accelerate. It sounds so amazing. I can see where non res might be too much noise for some people, but I absolutely love it. It almost makes my ears ring
.