Been chasing this for a while now.
LTFT B2 likes to sit around +20% at idle and up to 3000RPM B1 will sit at about 12% at idle and drop to 6 at higher RPMS. It is also beginning to buck a bit when cruising will little gas. Will begin to misfire 4 & 8 about a minute after cold start and stop on its own once warmed to operating temp. New MAF, Plugs, COPS, Injectors, filter, O2 sensors, intake manifold (had runner controller fail and studs on manifold broke), throttle body (it actually died with code) Compression test: Highest was 209, lowest was 190 (4 and 8 were 200 & 209 resp).
OBD fuel rail pressure is good (though I'm not sure how dependable it is with OBD)- it does rise and fall with accel/decel.
Cannot find any vacuum leaks.