Pull some plugs and see if it's really running lean, or if you possibly have one or more leaking or stuck injectors. Cylinder balance test helps check that too. Check fuel pressure, if it's low the more distant bank may not get enough juice. Pull O2's and see if they're nice & carbon coated - newness may not indicate condition (though '07 was 9 years ago now). PIP code might not be false, again 9 years is getting up there.