Rshustler1

Just going out on a limb here but it sounds like there is a hole In The exhaust somewhere around the muffler. Or the mufflers have a weak weld and are rattling and at high rpm more flow and noise drowns it out

rls82959

Quote "As you turn on the car and the idle is around 1k it sounds normal,
but as soon as it goes down to 600 700 idle it does this putting sound"

Quote "We cut out the y pipe and did 2 straight pipes from the catalytic converters"

Been there, heard that. Yes I had that sputtering noise without my H pipe.
I could bump the idle up to around 800rpm with the tuner and it would go away.
I installed an H and the the sputtering was gone under 800rpm.

turbo 2.8

negative ghost ride! the h pipe has a small pipe that connects both exhaust pipes giving it the look of the letter ( H ) this helps balance exhaust pressure or back pressure. I'm betting the straight pipes are your issue

pascal

Straight pipes is your problem...

X3xMONGOOSEx3X

that's what she said

Austin05mustang

Well I fixed the problem somewhat, the tips had a concave sort of deal on the inside of the pipe so it was backpressuring and pushing through really fast which caused the noise. It still does it but very very faint, although now at very high rpms it sounds like a rice rocket. it makes that rattle sort of sound. any ideas? ):

pascal

Damn right!
She won't take none but the XXX ones!

157dB

Even fire V6es dont gain anything from an H pipe
except to stop the sputtering at idle RPMs.
Allthough...
It has another function all together on the odd-frire V8s.
To even out the odd firing pulses as seen by the mufflers (2).
V6es fire left bank, right bank, left bank, right bank and so forth.
V8s fire left side, right side, left side, right side, right side, left side and so on.
They make headers with cross over tubes to fix the exhaust gas scavenging problem
eliminating the H-Pipe on V8s.