After installing BBK LT's and an O/R H-Pipe I've got this small problem...
 

Alright. I recently had BBK LT's and an O/R H-Pipe put on my car to replace the stock manifolds and vrs o/r x-pipe. But I kept the Maganflow catback. Now...when I'm driving I hear a hissing sound. Kinda like a leak. It gets louder the more I step on the gas, and its annoying as hell. I am like 99.9% sure its not a leak. This noise comes from underneath the car (not a header leak thank god!) I was told I'd hear some crazy noises with the addition of longtubes, but I never imagined they would do this Seems to be in the same location as the mufflers. Perhaps before with an x-pipe with a straight through muffler...it didn't do it. But now with a h-pipe I need chambered mufflers?

Is this true? If so, can you recommend a comparable muffler in noise to my magnaflows and that would sound good and fit well with the rest of the magnaflow catback?

Thanks a lot. I really appreciate it.
-Matt

It has to be a leak of some sort. When you bolted the catback back up did you evenly tighten the bolts from the catback to the H-pipe? And same with the bolts from the headers to the H-pipe? Do you have a gasket in-between the headers and the H-pipe? check all of those and see if it still does it.

I have BBK full length headers and an o/r H-pipe with mac catback and I have no hissing noise like you described.

You don't need chambers, you need to fix the leak. It is entirely possible you have one you can't see.

undo all the bolts there and put it back together.

BBK
 

MY FRIEND....

CALL BBK OR BROTHERS PERFORMANCE IN CA. IF YOU HAVE DOUBT FOR WHAT IM GOING TO SAY.

1) THIS NOISE WILL BE LOUD/DIFFERENT AND ECHO SOMEWHAT.
2) THE HEAT UNDER YOUR FEET IS NORMAL.
3) THE CHAMBERS, ITS UP TO YOU.
4) THE LT AND O/R H PIPE ARE MADE FOR EACH OTHER FROM BBK AND IT ISNT NECESSARY FOR THE GASKETS (THIS IS WHY THEY DONT COME WITH GASKETS), BUT YOU CAN BENEFIT BY APPLYING SOME[ALTHOUGH THAT ISNT YOUR PROBLEM]
5) TRACE THE BOLTS AND LISTEN BY USING A TUBE OR WATERHOSE(TYPE) TO EXTEND TOWARDS EACH HEADER BOLT AND TO YOUR GOOD LISTENING EAR. LISTEN CARFULLY AND COVER THE OTHER EAR TO FINDOUT IF THERE IS A LEAK FOR SURE. [THIS IS THE OLD FASHION WAY]
6) IN MY BBK LT FINDINGS, THE LT TUBE THAT EXTENDS BY THE STEERING SHAFT WITH THE BLK PLASTIC GROMMIT(SP) HAS A BRASS NUT THAT WILL CONSTANTLY WORK LOSS AND MAKE YOUR TICKING NOISE.
7) MAKE SURE YOUR FLANGES AND BOLTS ARE HORIZONTAL TO THE FLOOR AND YOUR CLEARANCE WILL BE IN QUESTION WITH LT.
8) IF IT IS IN THE REAR OF THE VEHICLE, IT SHOULD BE EASILY FOUND BY ANY THREE STAR MUFFLER PLACE.
9) I WOULD QUESTION THE HEADER GASKETS PROVIDED.
10)CHECK THE FLOWTUBE BEFORE THE MUFFLER, THEY CAN SPOT WELD THAT IF ITS THERE.

NOTE: WHEN YOU CHANGE THE FLYWHEEL AND CLUTCH...MAKE SURE YOUR INSTALLER REMOVES THE PASSENGER SIDE HEADER....NONE OF THIS HALF ***** STUFF OR YOUR NICE HEADER WILL TAKE A BEATING.

TAKE CARE AND SPANK A VETT FOR ME....

JETT

Thanks guys! Any more ideas? It's only on the passenger side of the car and although I've never been on that side when someone is driving the car, my girlfriend says it sounds like its coming from the back...not the front thank god!

Took it to a shop today...he looked for any possible leaks but no luck. :(