Catalytic Heat sheild covered under warranty?

[cgspies]

I remember hearing that the '02 Silverado's have a 70,000 or 75,000-mile warranty on the catalytic converter. Well, the heat shielding on mine is starting to rattle and vibrate pretty loudly, at about 49,000. I was wondering if anyone here knows if the heat shielding is covered under that warranty.

Thanks,

Chris