Sr20 Rattle/backfiring Help !

[1slow24d]

I have a red top sr20det on my S13, and its making this rattling noise from the turbo side of the motor. It sounds like its coming from the turbo but i just replaced it for another t25 because the other one i had, had a lot of shaft play but it's still making the same rattle.

It rattles at start up idle, under slight load like around 2k, and when shutting the motor off. It just rattles randomly, but when in the bay listening it sounds like rattling. When at the rear near the exhaust it sounds like little backfiring.

I checked timing and rocker arms under the valve cover, everything was fine.
Checked all bolts around the turbo, and its not the heat shield because i took it off.
Cant seem to see anything loose.

I feel like its misfiring and backfiring but cant seem to find a cause of it.
Here's a video of a car a found that is doing the same exact thing that my car is doing.

http://www.youtube.com/v/n300hFFKliM?fs=1&hl=en_US