kazandlee

Mine too, sound like hissing, as you say, just posted a similar thread before i came across yours, ive had it at three muffler shops, no one can fix problem, realy pissing me off too!!!, am going to e-mail maganaflow.

will let you know how i get on!!

04BlueGT

I have the Magnaflow catted X and cat back. I installed them a few months ago and no issues. As far as hissing, that does not sound like an exhaust leak. Usually, you get a ticking sound. Exhaust doesn't continually flow through pipes like an air hose. The ticking is the leak being hit by every pulse of each cylinder firing. An intake may hiss/whistle, but I've never seen an exhaust do it.

One thing about the Magnaflow cat backs it that you cannot use their instructions. You have to put it together back to front and loose fit everything before tightening the bolts. That is how you tweak everything into place.

Emanpimpster

well i do have a steeda cai but i doubt that would make the noise i dont think it started until the exhuast got put on. What else could the hiss be? I think ima email magnaflow too