06 Silverado, 2 wheel drive, 5.3L, 4L60E (cold air intake, performance coils, SS headers, Corvette servo, and holley reprogrammer) So 10/26/23 took truck across town and back ran fine. Two days later jumped in and it started then acted like the fuel pump shut off or the ignition quit. Cranks over but nothing. Let it set for couple hours and the first try it kinda kicks off then does. I checked all fuses,you can hear the pump and if you hit the Schrader valve on top of the intake it's got pretty decent pressure I have not put a gauge on it but seemed ok, and only codes were knock sensor and evap canister. (been off and on for years) If anyone has any ideas I would really appreciate it!!

 

what were the full codes and titles?

I would fix those. They can cause performance issues. Troubleshoot them on obd-codes.com

Your mods kind of throw a wrench into the mix.