I've never heard of an O2 spoof either.
You can gut your cat, but I wouldn't try to run without an O2 sensor. The computer relies on the O2 sensor readings to decide how much air and fuel to mix. Without it, it will default to a fairly rich mode, and you'll get crappy gas mileage, and probably worse performance.
Before fuel injection with O2 sensors, the computer just had to make a rough guestimate as to what the best ratio of air to fuel to use. The O2 sensor helps it be a lot more precise.
I'm not sure why someone would think running without an O2 sensor would be an improvement.
1996 Olds LS, 198,900 miles: RIP...