Tune it out!
Follow the same instructions that
steve99 posted -- There's more info in this
thread, which is what I used to tune mine out.
Here's the difference it makes on my car...
----- Before -----
[ame="https://www.youtube.com/watch?v=sbrWfXa_qmQ"]Scion FR-S Borla UEL / FT86 SpeedFactory V1 Cold Start - YouTube[/ame]
----- After -----
[ame="https://www.youtube.com/watch?v=8rrfXthK_dc"]Scion FR-S Cold Start "Quiet" Tune - YouTube[/ame]