Have a 2002 3.0 auto that bucks over ~3500 on highway,as rev limiter does similar in N/P. It also shows codes PO305,306 and later Bank2 lean oxy code. I have replaced plugs ,wires,coilpak,cam syncronizer,compression is ~150psi,fuel rail is 65psi, MAF voltage is good,Noid lights flash on inj harness, valve springs are not broken.
What could be causing 5/6 misfires?

 

Think I located it.
After doing the coil pac,good noid light,fuel pressure,compression,valve springs,Maf voltage, etc pretty well narrowed itt down to a vacuum leak,OXY,cat.

Did a vaccuum test and was only ~12 no where near 17 min needed. Then pulled bank 2 Oxy and it was black,disconnected the maf for default. Started truck and I could hear the back pressure,it already started running better. Pulled the left cat manifold loose and ran it. No more misfires,quick reaction up up to governed 3000rpm,vaccuum went up to ~18, just some codes for maf,oxy,etc being disconnected. Reconnected maf,still ran smooth with just missing left cat code. So I'm thinking a new front cat,oxy should fix all misfires.