Rattling noise coming out of exhaust but no noise at engine bay. Turbo is taking longer to spool up and its blowing more smoke. Not sure what to check. Once the turbo spools up it runs normal.

 

I hope you have a boost gauge as this is an excellent indicator of the health and performance of the turbo.
If not I would recommend that you install one.
The boost gauge will tell you what your next step should be.

 

I do Have gauges. The boost seem to take longer to build, but once it does it runs great