Car is a turbo lsj with blow thru maf. Narrow band and wide band sensors less then a year old.
From a hot start, the car will show +5 ltft on average. After about 15 minutes of driving, ltft make a subtle swing towards -6 on average. This makes it damn near impossible to tune the maf. With fuel trims off, the wideband shows the same trend of lean to rich given enough time.
What are somethings to check and look at?