Catalytic Converter Removal

[Lone Star]

I'm thinking about removing the cat from my car. Are there any special considerations I have to take into account. For instance is there any sensor that runs to it that will tell the engine management system that because the cat has been removed that its now running rich. If so, what do I have to do to combat this? Are there any other issues that I have to take into account? Obviously it has to be put back on for its MOT.
Cheers
John