[squish72]

Originally Posted by arpad_m

The reason, as far as I know, is to warm the cats quickly enough to meet stricter recent cold start emission requirements. Your only "official" option, as people advised above, is to enter accessory mode and set the exhaust to stealth mode before you start the car, and even then it won't be quiet, as in, Accord or Camry quiet (which is a good, no, GREAT thing IMO).

Now, as an interesting thought experiment, I do see an option in the tune that allows defaulting the valve state to closed. Has anyone tried this by any chance?

Actually to only change the startup sound for the different modes its under exhaust rumble enable