Originally Posted by levani041491

I have OBX test pipes , Y pipe and topspeed PRO1 exhasut , car was very raspy from 2500 to 3500 rpms . I took to my shop today and FIXED it !!!

tried few things
STOCK cats + OBX Y pipe+Pro-1 exhaust = RASP almost same
Test pipes + OBX Y-pipe + stock exhaust = RASpy

Test Pipes + stock Y pipe + Pro-1 exhaust = NO rasp at all NO hissing on deceleration


all the hissing was coming from the flexpipes on the Y pipe . I know stock Y pipe is small but 2.5 test pipes gos into 2" Ypipe and then comes out into 3" exhaust so it cant be so restrictive , it will actually increase velocity