What could explain all of your codes and symptoms is a failing Ignition Control Module (ICM). It could account for the misfire code, oxygen sensor code, and poor performance. This is a problematic component that I recommend replacing every 125,000 miles or 10 years, whichever comes first. On many cars of this generation, you need to apply silicone heat transfer compound to the back of the ICM; otherwise, it won't last long. My sense is that you are very close to solving this thing. I really think a bad ICM is at the heart of your problems.
I'm assuming you replaced your Camshaft Position Sensor, otherwise that could be part of the problem. It smacks of being a bad ICM, to me.
