Rattle In Drive

So I stop at a light today and realize I have a rattling noise. I cant hear it from outside the car, only inside from what seems to be the passenger side.

It ONLY does this in Drive. I checked the tranny fluids and its good and clean. Shifting is good.


Any ideas?

I dug around and cant find the source, it doesnt seem to come from the tranny but than again it only does it in drive!

I have an odd feeling it may come from the exhaust, but not sure if having it in drive would cause the noise here.

I'm guessing....catylitic (sp?) converter. mine rattled for a long time and only in drive. It was very annoying. I think it was a little over $100 to have the new one installed.