Alright, before I go out and buy a 60 dollar catalytic converter, I wanted to check with other sources. Lately, if you push my car into boost, it feels like after a second it gets all the power sucked out of it. It doesn't stall or anything, it just looses power. This only happens at high RPMs, mainly. It'* also getting bad gas mileage. Is this a bad cat or what?

In my personal experience with a VERY similar problem, my fuel pump was dying. As it got warmer, it couldn't flow as much or hold pressure at high volume. But it was accompanied by decent MPG simply because it supplied less fuel than it should and kept me out of the boost.

Off the top of my head...

This could be KR from your exhaust manifold cracks (if you still have them)
Could be KR from ignition related items (plugs/wires)
Fuel pressure
Cat
Dog
Monkey.

He does have some pretty nasty cracks in the EMs. We did a seafoam on it and smoke BARRELED from the EMs upon starting it up. His plugs and wires are new.

Also, we were on the way back to my house from Wal-mart, and he floored it to about 85 from 55 on a country road, and after that I could smell the infamous rotten egg smell pretty stongly. So it comes to my opinion that his cat is clogged, cause that was almost 6 months ago.

We also never got to check the fuel pressure for real, just at idle in park.