Repair your misfire first, then re-assess the fuel trims.
If you have the 3.9L V8, your coils could be the issue. There could be an oil leak at the valve cover gasket that leaks oil onto the coil boots, causing deterioration. This is a good first place to look.
On the 3.0L V6, you still have coil on plug, but not the oil leak issue. Still, a misfire could e caused by faulty coil boots or plugs.