No, just terrible noise.
Gutting the main cat makes the flow through it turbulent.
You're better of removing it entirely and then installing a high flow resonator in the middle of the exhaust (which requires you to remove the POS stock one in the process).
More power is gained from gutting the precats on a V6, but that requires you to run a main highflow cat in order to pass emissions (if you're in a state that gets tested).
