Any help is greatly appreciated. The idle of the truck will start to fluctuate violently after I sit for a while, I might just be sitting in park or at a redlight while in drive. If I don't try to rev it up or I throw it in drive or park it tends to shut off. It's shooting codes, left and right bank too lean......? I've replaced the Iac valve and the Egr valve and its still throwing same codes and giving me the same problems. Any suggestions...it's starting to be a pain in my $&@! Thanks

Check the wires to IAC, I don't know what their specs are, but I'd check the wires closely for breaks inside the insulation.

Welcome to the forum. All engine codes as well as the trucks year and engine size should be listed so people can help you. It's all a guess with out a starting point.

Normally lean codes are not addressed by changing the IAC or EGR.
You likely have faulty hoses or rubber parts connected to the intake manifold allowing air to enter as the vacuum pulls the crack open.
You need to supply the codes because, as you have done, miss interpeted them, and changed parts that are not the cause of the issue.
Good luck.