96 Accord Misfire at certain RPMs

First I want to make a couple of comments about what you have done so far.

The computer says that the misfire is occurring in cylinder number 2. This means you want to look at things that ONLY effect this cylinder. A new throttle body (or TPS sensor, not sure what you mean), PCV valve, distributor, and map sensor would effect ALL the cylinders, meaning you would most likely have a random misfire code instead of a misfire localized to a particular cylinder. So these things could not have been the problem.

Also, it is not a good idea to just replace one fuel injector. The reason for this is because the computer cannot tell what the fuel mixture is in each cylinder. What it does instead is to probe the exhaust stream for oxygen (using an O2 sensor) and see how much oxygen is left inside the exhaust. There is a direct correlation between how much oxygen is in the exhaust and the fuel mixture. When you only replace one fuel injector, that injector will operate differently than the others and have a different spray pattern. All the computer can do is compensate ALL the injectors fuel, therefore causing an imbalance and possibly create even more misfires.

Now that that is out of that way. Start with the basics. Check the plugs and wires. What is the condition of the plugs? Does it show signs of burning oil? Running lean? Running rich? ect..

If that is good, the next thing I would do is a compression test on all cylinders and compare the results from cylinder number 2. After that, I would do a leak down test on cylinder number 2.