I have been having intermittent issues with this 00' LS 4x4 since almost day one. I hate this vehicle, but the wife loves it. So, here I am.

I have replaced the CSFI to MPFI because we have had a mechanic tell us in the past that it was going bad, just finally got around to it. Still no start. Have replaced the fuel pump, fuel filter, flushed all old fuel out and added about 3 gallons of new fuel. Stutters, but wont actually stay running. The stuttering is intermittent, most of the time it just cranks. I have put fuel directly into the throttle body, the engine runs long enough to burn that fuel off, then dies. I changed the fuel pump because I have tested the fuel pressure before, and it never got above 50 psi. I havent had a chance to test fuel pressure with the new pump, just figured/hope it would be good.

Not sure what else to add. Ask away, I will check back atleast daily.