Car won't stay running after knock sensor replacement

[Tallon535]

Hey guys, I need to pick your brains for a minute. I have a 2000 Pontiac Trans Am. FLP headers with high-flow cat y-pipe, borla catback, LS6 intake, SLP air lid, March underdrive pulley. It has 93k miles and a 6 speed.

I replaced my knock sensors today and had to remove the fuel rail, intake manifold, throttlebody, maf sensor, and air lid. This is the third time now that I have removed and reinstalled the intake manifold. The two times before was for an LS6 intake install that sprung a coolant leak.

Anyway, we have it all put back together now and the car won't stay running. It starts right up first try, idles really high like around 2k or so and then dies. It doesn't sputter or start to choke or anything it just flat out dies. You can smell gas afterwards.

We have checked all the connections we can find and everything looks to be hooked up. The fuel pressure is fine, we checked it with an external guage. There are no vacuum lines disconnected that we can find and there is no air rushing noise in the engine bay.

The car was running perfect this morning before it went under the knife and has never had trouble staying running or idling before. We are at a complete loss as to what is causing this problem.

Any help you can suggest would be greatly appreciated. Thanks!

[GEARHEADNATE]

Did you install new intake manifold gaskets, they say they are reuseable but I don't trust them. Cause it sounds like a vacuum leak to me.