Nismo
02-19-2008, 06:43 PM
My car is making a sound like its blowing off when it starts building up boost. I checked all the lines and they dont have any leaks, I even changed out the vaccum line entirely. I changed out the BPV's because I thought it may have broken. I can rev all the way out to rev limit in vaccum with no problems, but its only when I build boost does it make the noise. The only think I can think of is that the cat is breaking apart and clogging the secondary cat. This just randomly started one day. It was boosting fine then this occured. Its a vortech supercharger on a scion tC btw. Everything about it is stock.