exhaust sounds buzzin?

[hmuminovic]

i've got a 1.1i sx with a jap style back box. last week i had bigger bore piping done on it and made it a staright thru de-cat system. it sounded propa nice and loud for the first 3 days, and now its started to make a buzzing noise after 3000rpm! does anyone know wot could be causing this, is it the back box?

[samcook]

could be blowing from one of the joints

[DAZ1985]

Could be the center section vibrating on the heat shield. Get underneath and wedge an old exhaust rubber between the exhaust and the heat shield.

[hmuminovic]

the noise is only comming out the back box not the piping. all the piping work is as stiff as could be, but its like the baffle in the exhaust is fooked up or something. anyone else had this problem?