I've gone through your post again and would like to ask you - if the LTFT and the STFT are of positive or negative values ?
Lets say it´s only positive values you got from LTFT & STFT, then your are dealing with a lean condition, which by the way fits very well with the diagnostic trouble codes P0170 you got from your ECU.
A lean condition can happen from multiple causes - an air leak somewhere in the system could do this. But as you already have smoke tested the intake manifold and found nothing abnormal - the socalled "Lean Condition" must come from another source.
That other source could be low fuel pressure or partly clogged fuel filter or a bent fuel line - it could also be your fuel pump running at a lower speed caused by a small voltage drop to the pump.
So its vital that you check your fuel pressure is in good shape.
I´ve seen your last WOT test and at steady 2000 rpm the lambda seems to work correctly - but its a other story when it comes to the full throttle test - it aint to happy to make the transition from lean to rich condition, which is expected under the full throttle test - most of the time it shows a lean condition !!!.
There are ofcourse other things to check, but I would focus on everything that could make the ECU think - that it got a lean condition.