catalytic converter rattle help needed

[lj03]

my cat is rattleing from inside been told part of the honey combe inside has come loose?
its a milltek 100cell sports cat.
it doesnt stop the car from running and runs fine just has an annoying rattle but only when car is stood still on idle!! do i need a new cat?? it passed mot like this. will it be okay if i dont renew it straight away????

 

[Dabbalz]

It's more than likely a heat shield thats rattling, if not, when the cells break up they might end up going into the silencer and vibrating when you rev the engine. I had this on my RX8 and JCT600 had to replace the Exhaust as the cat had been changed just before i got it but not the exhaust.
It's annoying more than anything!

 

[rk696]

Doesn't it have a warranty with Milltek?