You can bypass the fuel relay, but I wouldn't suggest doing so.
The "special" thing that makes the vats work as far as the key is concerned is the little black chip looking thing in the key itself. This is nothing more than a resistor and there were only fifteen different resistance values or "codes" that I ever remember reading about. If you look in the area of your steering column you'll notice two 20 guage (?) (really skinny) orange wires running up the column. These wires are connected to the ignition lock. They are used by the theft module to read the resistance of the key. You can splice these two wires and place a resistor in line (module side of splice). So far (I haven't done a million anyways) the resistance values needed have been in the 2-3 K ohm range. You can be within a few hundred ohms and be good to go. Go to Radio Shack and buy an assortment of resistors from the 2-3 K ohm range (they're real cheap). Place them in the splice one at a time and keep trying until it works. It would be real easy if you had the 90 key, that way you could just measure resistance from the key itself.
I've done this a few times now and it's worked for me anyhow.