ok i have a oem style bosal downpipe, ebay resonated test pipe, walker midpipe, and bosal muffler. upon installing all of this anything over 3500 rpms the muffler produces this buzzing tone. i tripple checked and there is nothing touching or vibrating. i re-installed my leaking catlyitic converter and the buzzing barley got any better. im assuming the bosal muffler just sucks.

I want the car to be stock and quiet, should i just put the not leaking resonated test pipe back on and buy a different aftermarket muffler? any suggestions on what muffler to buy to keep the car quiet with NO buzzing?