4pipes

While looking under my car I saw that the left rear resonator, right before the differential had a large flat crimp in it. The right one is perfectly round. I thought it was a defect, so I remember photos posted by Ford of the exhaust on the net.

Check out this pic:

http://www.mustangexhaust.org/wp-con...ad-exhaust.jpg

The crimp must be some kind of tooling relief or sound tuning, we all must have it.

PTRocks

I am pretty sure it's there to prevent drone by tuning the resonators for slightly different frequencies.

4pipes

That's a great explanation. I really couldn't imagine anyone installing it with such a large flat if it was defective.

m4a1mustang

I noticed it on my standard 5.0 as well. At first I thought it was an issue, but like you guys, after some searching around I determined it was some sort of sound tuning.

06GT

they all have them...the other one on your car is the same, but rotated so the crimp faces the floorpan

m4a1mustang

Good info