well its illegal so if you have state smog checks I wouldn´t suggest it. you can probably pass the test without it though.
they really aren´t that big of a plug like everyone makes out. if you are really wanting the couple extra points of a HP get a high flow one and be done with it.
Like egtdude said they really aren´t much of a restriction. They are probably less restrictive than some "so called" performance muflers. In the old day when they were first coming out with cats they could be a problem, but with the new designs they have now it´s not much to worry about. If you look into one, it´s basicly just a honeycomb of the catlyst meterial, and you can see right trough it. Besides if you yank it you will have to find somthing to replace the gap there, which usually means goung to an exhaust shop to get them to make a pipe to put there. And they might give you shit about it because they arent´ technicly suposed to do that stuff. As far as the check engine light. you shouldn´t have a prob since your car is a 93 and still uses the OBD-I engine management system. The 96 and newer cars that use OBD-II have an oxygen sensor before and after the cat to tell the computer how well the cat is working. Theoreticly the second O2 sensor shoul read way lean since only clean air should be hitting it. If you took the cat off in one of those cars you would be getting an engine light all the time, but they sell dummy sensors to fix that problem. But as far as power goes you may get an HP or two, but nothing worth the trouble of taking it off. Unless you only use your car for racing, and that´s it, I´d just leave it.
Being OBD-I is awesome...Anyhow, yes you can get some extra horses from it. But, I say open up your exhaust all the way first. Have a muffler shop build you a test pipe "for track use." And then you can pass smog when you need to and just gain the horses when you want to.