Silly tuning question

zuperman 370

Hey guys I hope that I don't get a lot of heat for asking this question, a friend of mine told me that after I tune the car and adjust the AFR, there is a chance that the hiss and a bit of rasp may reduce due to the AFR being adjusted, right now my car is not tuned of course, mods that I have are FI long tube headers amuse y pipe amuse stti exhaust, sounds good, but when I'm driving and I remove my foot from the paddle or down shift there is this annoying loud hiss, like Exess air coming out of the exhaust or something and it's really annoying, so will a tune and adjusting the AFR reduce that because in some way you are adjusting the air that comes in and out of the car? And second question is that I just recently installed the y pipe, had the other mods on way before that, will the rasp and hiss reduce over time once the y pipe breaks in with the other parts?