I have a 2000 Honda CRV with an exhaust rattle between the catalytic converter and resonator. Rattle can be heard while driving slow and at idle. Checked under vehicle with engine running and while off. It's definitely not coming from the heat sheilds. I gently knocked on the pipe where the loudest rattle was coming from (near the resonator) with the engine shut off and could hear a rattle that sounds like maybe a piece of metal or broken cat material is in there bouncing around. After a google search, it sounds like Honda used a double wall exhaust pipe and the inner and outer pipes are hitting each other. I've never heard of that, so I'm a bit skeptical unless someone else here has personally encountered this as well. Apparently, the fix is to drill thru the outer and weld it to the inner so they are not free to move or vibrate against each other. The rattle is just loud enough to be annoying. The connections are welded, not clamped, so there's no way for me to easily inspect inside. Can someone tell me if this is the wrong diagnosis? If the double wall sounds like the cluprit, then is the method above the best way to cure it, or is there another way to go about it? Any idea how much i should pay a muffler shop?