Exhaust Rattle ARRRRHHHHH

[theinfamousdrew]

Ok....where to begin?

Exhaust setup:
catless DPs
N55 mids
Stock muffler

The other day I installed a set of Raceland downpipes.
Fitment was good, no issues installing them at all.

On the first start up there was a horrible rattle at low RPMs and low speeds.
I put the car back up in the air and loosened everything and realigned everything.
Now the DPs weren't hitting anything, everything was tight.

Now I still have a rattle that I cant figure out.
It happens with a high load and low RPMs.
From a rolling start around 5-15mph and put it in 2nd it vibrates and sounds like an old Honda!

I did notice that the install of the new downpipes changed the angle of the exhaust.
This change was causing the rear muffler hanger to vibrate against the pipe near the midpipe/muffler flange.
The hanger is adjustable so I adjusted it so it is no longer hitting it, or at least I think so. I shook the pipe trying to replicate the noise and I couldnt.

My thought is that it could be hitting a heat shield or something.
I was thinking of trying the stock midpipes again. Im not sure how much HP/TQ I would loose by putting those back in though.

Im hoping someone out there was encountered the same issue.

Thanks!




****UPDATE****
I had a friend come over to help me today.
Seems like its not really a rattle, more of a raspy exhaust note at certain RPMs.
We put the car in the air and revved it up a bit.
You couldnt hear a rattle coming from anywhere, the noise was coming out the exhaust.

[crew_chief152]

This happen to me. Took me a while to figure it out. My clamp that goes on my mid pipe fell off. Hard to notice at first.