I think something is up with your boost control. Looking at the logs you posted, you were seeing boost pressures significantly higher than they should have been, which can cause the p0171 since your ECU isn't tuned for it. I would make sure that all the vacuum lines for the wastegate and boost control solenoid are all intact and in place, and it might be helpful to get a boost gauge if you don't already have one.
If you don't see anything under the hood that looks suspicious to you, I'd definitely recommend taking it to someone else for a look.