I want to fit my rear o2 sensor with a simulator so i can cut out my catalytic converters and fit on my own custom exhaust. Any ideas, opinions, or objections?

 

The cats are installed for more than to just increase the resistance on the exhaust line and cut down engine power. As far as I know, the after-cat oxygen sensors are there just to control the efficiency of the catalytic converters, so if you leave them out you'll get a check engine light, while the engine will run as usual. The bad part is that they are mandated by federal regulations so that your car is polluting as little as possible, and you get a warning when the cats stop working. So if you want to cut the cats for an off-road-only, race track application (kinda' doubt this, given you're asking about a Ford Exporer ...), you won't need an oxygen sensor simulator. If you plan to do this for a federally-registered car, then I'm sorry, but I will not tell you what can be done (although I know how to do this) because it is illegal, and we're here to help people, but not to help them break the law. I hope you understand ...