He means if you replaced your pcm, you'll need to get blank PATS keys and program them to your new PCM, otherwise your car won't start. I'm suessing you'll need a new cylinder for the steering column and new door/trunk locks if you don't have power locks that'll work with keyless entry.

1999 Silver Frost SVT #609 of 2760 Quaife, lightened SVT Flywheel, SPEC stage II clutch, removed resonator, k&n drop in - various other goodies too.