I have this strange buzzing/rattling noise when my engine is warm and decelerating.. When I accelerate, it goes away. I can't figure out what it is. Any ideas?

 

Might be the heat shield for the main cat.

 

I checked that, but that wasn't it.
To give you a better idea, it sounds just like putting a card on the front forks of a bicycle to click the card against the spokes as the wheel rolls.. Like what the kids did back in the day.

 

No one?

 

I have the same exact problem, only rattles on decel under 3kish rpm's. Took it to a local rotary shop and they said it was something inside the turbo manifold and only way to fix it would be to replace the whole manifold but i dunno.

Richard