Do I need a new CAT? Options

[ShadowPhantom]

When I first start the car and give it some gas the car sounds like a gurgling terd. Once it warms up it is much less noticeable. Sounds almost like a little marble bouncing around by the exhaust manifold with a bit of a sputtering sound. It only does it when it is in gear not when you rev the motor.

Anyone have any idea what needs to be replaced? CAT or manifold?

[bindertch]

could be a crack in the cast iron manifold. the 7afe cast manifold is known to crack, usually between 3/4 or 1/2.

I second this. I bought my car and then found the leak. It could also be the flex pipe.( the little mesh tube piece) Those are bad about leaking that could be caused by bad front or rear engine mounts. It is supposed to flex a little but if your mounts are worn then it is flexing it any time you change gears or accelerate.
Easy way to check these is to: for the manifold just remove the heat shield and inspect it, for the flex pipe you need to jack the car up and feel around it while the car is running.
Good luck and ask more questions if you have any.