Joe Muckle

I have a 2012 5.3 Vortec Silverado 1500, I keep getting rich left and right bank codes, the truck starts very hard cold. When it does start it is very loaded up with fuel. I cleaned the oxygen sensor and also checked fuel pressure, it has 57 psi with the key on and drops to 42 psi when running. Looking for some input to fix it, I’ve been a heavy equipment mechanic for 40+ years but don’t work on any of the newer fuel systems.