JDM Type R header/Cat

I have a JDM type r header w/a testpipe right now, and everytime i let off the gas there is this raspy buzzy sound that comes out where the cat,collector hook up at. I'm not sure if there is a leak or if something like one of those dounuts needs to be in there, but what kind of high flow cat would you recomend to go w/the jdm type r header? thanks

Todd

What do you mean raspy buzzy sound? Any rattles? Maybe you can describe it in another way and i'll try to help you .

it occasionally rattles, but for the most part it sounds almost like air is leaking out from where the collector and the testpipe meet. It makes a raspy sound when i let off the gas, or go to shift. It mainly starts to make that noise at 3500rpm or more, and you dont hear it as much when I step on the gas, unless i am flooring it. I hope this helps explain the problem. Thanks.
Todd

Check the gasket on it. Maybe you used the wrong one? Did you use the one that came with it? If you did then try to see if the bolts are on tight. It doesn't like a big deal. Maybe its normal since it does have the 2.5 collector.

that's how my brothers car sound like when we first put the test pipe on his car now it doesn't really do that..after a while it'll probally go away..it's caused from the test pipe because the cataylic converters have fliters type to filter the air coming out while the test pipe just let it flow out thus making your car sound like it's hallow...

yeah thats true, i think i should take the bolts off, and get new ones, these seem kinda janky, and check the gasket to see if its the right one. thanks
todd