Lean can also mean vacuum leak or lack of ignition to ignite fuel. If your plugs are over 80k and haven't been changed now is probably a good time as this can be your problem. Another likely problem is a coil that is going bad. A bad coil will not always produce a misfire until its failure progresses. You're order to confirm before you start spending money you may want to swap all the coils in bank 1 with bank 2 and if the lean condition changes side then you can try swapping one set at a time until the lean condition returns to tr other side and allowing you to pinpoint bad coil.

 

That's a good idea...I did buy a new fuel filter and fuel injector cleaner still need to insert them. Plugs are only 7k miles old