Best Way to Turn Off CEL?
 

Since I fixed my o2 sensor I unplugged my battery for 10 minutes and also my 7.5 Amp marked (back up Radio) because that's what many places online said to do, but it still turned back on. Next idea?

In some vehicles you can turn the ignition like you are trying to start the car while the battery is disconnected. This will clear the computer. (not sure if it works on the Hondas)
If you have an Autozone nearby, they will let you use their code scanner and you can use that to read the code and clear it.

go check the cel code again, i'm guessing you didn't fix the problem

Disconnecting the battery or pulling the fuse is all you need to do to clear the codes on a '99. Turn key off first of course.

Do that, then turn key on and don't start and read codes. It should be clear (unless there is a sensor fault or other problem that is immediately detected). If the CEL later comes back on and a code is set, there is still a problem.