catalytic converter mods/removal?

My buddy told me that maybe adding an airhog filter and gutting the cat converter would add some power to my 90 olds 88 royale. Is this true, and what are the down sides?

The Airhog filter is the same as a K&N - good. Gutting/removing the cat - bad. Not to mention being illegal, the car would sound horrible. The engineers designed the engine to run efficiently with a certain amount of backpressure. The converter not only scrubs the exhaust of pollutants, it also provides this backpressure. An engine will not gain a thing from removing a properly operating converter.

On the contrary, I cut out the converter on my car and it gave it a bit more bark with the factory muffler which was definitely liveable. I would say cut it out. It gives you a lot more torque for movin around that heavy car. Take it from experience man. It makes a difference.