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OK, a blessing in disguise. It turned out to be a failing DOD/AFM lifter on cylinder 6. It finally failed to where you can hear it. That was the reason it only went lean on feathering the gas, it was when it was in 4 cylinder mode.
I have done several vacuum leak searches. I have replaced the PCV hose and the purge solenoid hoses. The injectors are new on that side and I even swapped the ignition rail to see if something was causing it on that side. I have change the gaskets on the exhaust manifold, I have changed the gaskets on the intake manifold, I have changed the gaskets on the valve cover to include the grommets. I have had the dealership check it and they did a smoke test and I have had another shop look at it and they did a smoke test. So far I am the only one that has dialed it down to the specific action that it occurs which is when you are barely touching the gas pedal. Anything outside of that the trims are good. It is just strange that it is on one side, which would make you think it was a vacuum leak. My last step is maybe the oil filler neck and gaskets. I haven’t changed that. It is on bank 2, that is the only thing I can think of. If it was the fuel pump or regulator etc. I would it expect the lean condition on both sides. I have tested the PSI on the fuel rail with a manual gauge and the psi was at 60. I monitored it yesterday and the fuel pressure stayed around 57 psi to 58 psi. It is just odd that it only occurs when the pedal is barely depressed and held in that position, basically the lightest you can touch it that opens the throttle position. Let’s say it is a vacuum leak I haven’t found it is odd that it would go lean only at that point.
I have checked the fuel pressure at the rail. It was around 60 psi. And when monitoring it while driving with the scan to it is around 57 to 58 psi. The long term fuel trim will shoot up to 18 on the initial throttle response, if you keep it lightly feathered it gradually increases up to 24.2 and will store a code. If you quickly throttle it and let go in that fashion or if you accelerate faster it won’t go high. On bank 1 it stays below 10 no matter the driving style. I will monitor the pressure at the initial throttle and see if it drops but I haven’t seen it do that before.