I know most of us honda owners go thru the mind breaking "Exhaust Noise/Rattle"
I have done some research and came to a couple conclusions or repairs.

The first one you can try is
1.Replace your gaskets from catalyctic converter to muffler.
2.Retorque your bolts.
3.Inspect your headers, and the gaskets, the gasket where the block and the heads meet, and the gasket where the 4 heads meet the 2-1 down pipe to cat converter.
Today I inspected my headers and found out that my gasket from 4-2 pieces seems to be in incorrect alignment with the pieces, you can see a bit of the gasket piece, which is not supposed to be exposed!
I will also try to replace my stock four head gasket, it might also be that its broken, but i will do ALL THESE STEPS.

 

make sure your heat shields are properly installed as well

 

what and where would the heat shield be?
are you talking about the heat shield that goes on the stock cat coverter?
i didnt install that when i installed the new cat converter, i didnt have the rattle problem up until i installed my new mid section arospeed pipe.
or the exhaust manifold, i removed that too when i installed my headers and never put it back.

 

okay that makes sense.... I didn't realize your exhaust was aftermarket so the heatshields have already been removed.... let us know what you find!

 

today i took it to the shop they found some loose suspension bolts they ordered the parts cus it was squeakin when i would thru bumps, but about my exhaust rattle he said he found an exhaust leak on my header 2-1 or "Y" pipe, hes gonna weld that area on monday and do the suspension job all for all like 100 bucs, they charge 65 bucs labor per hour and the suspension bolts are like 30 bucs , seems like a reasonable price for both jobs=$100
tomorrow im going to pep boys to buy new gaskets from headers to muffler.