2003 Ford Explorer 2003 Explorer P0205

I recently purchased a 2003 Ford Explorer 4.0L. I knew it had an issue when I purchased it. When it is scanned, two codes are present P0205 Injection Circuit Malfunction-Cylinder 5 and P2197 O2 Sensor Signal Stuck Lean-Bank 2 Sensor 1. When I start it, there is a definite miss and it smokes. Even worse, when it runs for a few minutes, raw fuel actually drips out the exhaust tip. I have replaced the #5 fuel injector as well as the entire engine wire harness as was suggested by a local mechanic. The end result was NO CHANGE. Where do I go next? Any help would be greatly appreciated!