I went to leave work on Friday and she would only run for 2 seconds and die. Literally exactly 2 seconds and instantly shuts off, no sputtering. I thought it might've been fuel line freezeup, since pre-windchill temps were below zero.

I came back this morning to check it out. I jumped the fuel pump relay to keep it on, and sure enough, I get full pressure at the fuel rail

Tried my other key. Tried key relearn procedure.. nothing. Its looking to me a like the crank position sensor... any ideas?

Check for spark?

She runs perfect for 2 seconds...theres spark. Then dead (no spark when dead, ha)

I know you covered all the bases, but it sounds like a security thing, then.

can you keep it running if you give it some gas?

Nope I can floor it and it revs fine but after 2 seconds shuts right off. Gunna check things out in the morning.

You were right on.

It was theft deterrant.
I wasn't getting any codes, but then I left the key to ON for a while and then read codes, and pulled up a P1629 "Theft Deterrant Fuel Enable Not Present"
I looked it up in my GM electronic service interface (yes, I have it at home now, and its awesome) and there was a service bulletin about 2001 and 2002 grand prixes having a certain wire by steering column get cut.
Instead of checking for that wire, I just used my powertuner to disable theft deterrant. I wonder what other effects this will have...
So yeah... took all of 30 seconds to actually fix.

Meanwhile, the tow truck broke my intercooler radiator. It hangs down a little bit, and I talked to the towing company about it and they ensured me it would NOT be a problem (I wasn't present during the tow). So now I'm in contact with insurance (the tow was through my insurance, free) to get it resolved. Unfortunately it will be a couple months till frozenboost.com even has another of these units in stock.
[the good news? I left 100% water in the radiator since I couldn't drain it all the way... there might be ice damage internally anyways!]

Good to hear it was something simple. I've heard of cars only running for a few seconds and it being a security thing.

That sucks about the front mount. Have you thought about going with a different unit instead of a frozenboost? I know that they are top notch pieces, but if it's going to take that long, maybe try something else?

If they give me a hard time (haven't yet) I'm just going to weld new mounts on. I haven't seen any other units comparable to this one, but I haven't looked recently either.
Anyway, the 2 month wait won't be an issue, since I won't be running the IC again till April anyway.