Flutter sound out of exhaust ?

[Racer57]

I had Dynomax mufflers installed (welded) 4-5 years(10,000 miles) ago. Dual exhaust without X or H. The driver side has a flutter kind of sound.  Is these mufflers capable to having a baffle come loose ?

[jimynick]

My smartass answer was going to be that it was the sound of $20 bills blowing out the exhaust, but in reality, I suspect you're right. If you can get it on a hoist or jack stands, a rubber hammer applied to those mufflers might find a different tune. Just my 

[Racer57]

Sound was a rusted out baffle. Installed MagnaFlow XL mufflers. They have stainless steel baffles, so hopefully they last longer. Car has a nice sound, but is about as loud as it was before. I had hoped these would be quiter,  but their ok. 

[Purepony]

Double check all bolts ?
Manifold bolts
Collector bolts
That's where I'd start

[RUNCHARGER]

Probably a baffle alright. Does the car seem a bit sluggish compared to before?

[Burdar]

Do you have a "weep" hole in the back of your mufflers?  If not, you should add one.  You can drill or punch a hole in the back of the case just above the back seam.  This will let the water drain out of the mufflers.  If you drive the car short distances and don't let the exhaust get up to temp, the water that collects in the muffler won't be burned off.  Then it just sits in the muffler and rusts it out.  You don't need a big hole...1/8" is about the max size.  If you use an "ahl" you can punch right through the case.

When I used to work at an exhaust shop, we punched weep holes in lots of mufflers.  It does make them last a lot longer...especially on cars where the muffler is at the back.  The mufflers take a long time to fully heat up.  I've seen mufflers rust out within a year when they are at the back and don't have a weep hole.