the plugs on the passenger side were carboned up (black)
the plugs on the driverside looked normal
01 expy 5.4 4x4 no codes

 

You are running rich on bank two, but not enough to throw a code. Make sure your air filter is service regularly and clean the MAF sensor. Try running a fuel/combustion chamber cleaner through it. You want to take steps to correct it otherwise you run the risk of damaging your catalytic converter on bank two.

 

Think the o2 sensors also control that a/f ratio. Might want to see what the ones on that side look like and possibly change them out.