Well I have had the warpspeed y pipe for a few months now, and since about the 2 week mark its been making this hissing (kinda sounds like the noise a helium tank makes if you understand that). I thought it was a broken flex so I replaced it with a triple ply, and had my warpspeed b-pipe installed at the same time. The sound is still there, if not a little more noticeable so I am wondering if it's a leak. Anyone ever heard of this?

 

Sounds like a leak.. it could be from between the y-pipe and the manifold...

 

I have the same problem with my HS headers, I am going to a shop on friday to have the whole exhaust looked over.

 

I just took my dad for a ride and he said it doesn't sound like any leak he's ever heard. He said it sounds like a slight rattle hitting so fast that its making the noise i'm hearing. I forgot to mention that when i put the y-pipe on, Each bank had one stud come out. So On both manifolds the y-pipe is connected by 2 bolts instead of 3. I just can't understand why it was fine for the first two or three weeks.

 

Bump. Could a slight bend in the flex section cause these noises? I thought I had a busted flex so i got the shop to replace it and I noticed the noise is still there on the new flex, but they bent it a little bit to get it to fit right.