Yeah, I think with the newer cars, you do need 2 original keys to program a spare. Is the fob the remote?
If so, and it's like the 96-97's, there is a connector in the trunk, drivers side, behind the carpet. It is next to the PATS module. Put the key in the ignition, turn it to on. Stick a screwdriver or something in the connector to short out the two pins in there-the door locks will cycle once to indicate programming mode is on. Then hit any button on each remote that you have for the car, one remote at a time. The door locks should again cycle with each remote to indicate successful programming. When you are done, turn the ignition key to off. The door locks will cycle one last time to indicate that programming mode is now off.
Good luck!
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T-Bones 1997 Cobra#6342 born 6-11-97
Wht/blk, Pro 5.0,FRPP 4.56's, aluminum driveshaft, FRPP throttle body, C&L 80mm MAF, K&N, Steeda U/D pulleys, Steeda timing adjuster, Flowmasters, s/f connectors, FRPP pro springs, BBK caster/cambers.
My old 96GT