So on my drivers side Crawford HFC, I am getting a pretty bad rattling sound from inside the cat portion itself. I know its not the heat shields or anything else. I put the car on a lift and had someone rev it, I used a prybar to hold things down to prevent movement to see where the noise was coming from. Its coming from inside the cat.

During driving it happens during accelleration (light and hard), and also deceleration if I leave the car in gear and no throttle. If I put it in neutral, it won't make any noise.

My question is, does this happen to anyone else? Is this covered under warrenty? This is the older style Crawford HFC with the support bracket still on it.