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?

[Bitter]

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