Finalizing this thread:

Replaced the battery today and it started right up. Took the car and had the alternator tested and it passed fine. Also replaced the serp belt since it was squeaking a bit. All good on that side.

have another problem that I will post separately.

Thanks!

 

Exactly, I am sure this is long resolved as I am just killing time looking at old posts, however, I had my intake manifold replaced on my 2001 MC SS and maybe a few months later I started having the same problem. It would start, stall out then start perfect. It would on occasion stall out when rolling slow like about to stop to turn. Turned out like you said, Bang, it blew the intake manifold off. (Luckily no fire) Turns out it was a simple fuel regulator, cheap part easy to change yourself. Unfortunately it ended up costing me 1100 dollars. I did get other work done as well. Intake manifold again, valve cover gaskets and such. Also my key switch the part behind not where the key goes in, (Still security light on occasion..)

 

While you are in your car, Lock your car with they key fob. Last unlock your car with the inside handle. Then try starting your car.