As I was saying in your other thread, I was using one for a couple years trouble free.
I believe with the 2.2 you have buttons to the left of the LED display vs the switches I had:
One of the buttons/switches (can't remember which) to the left of the display will toggle between advanced mode and the basic mode.
Advanced mode having 13 settings and basic only having one.
If you want switch between the modes, you need to first make the switch on the afc, then turn the car off and back on. When you switch between the modes all info from the previous mode will be lost. This is for switching between modes only not every time you change a setting.
The other button/switch next the the LED display is the edit switch. This will allow you to actually change the values your maf is sending to the pcm.
IIRC, the display will start blinking once you press it.
If your in advanded mode, and the edit is on, you should see the display blink 1 then 100.
If you hit either the right button or the left button under the LED display, the setting points should move up and down respectively. So, if you hit the right button it should blink 2 then 100. Hit the right button agian and it should read 3 then 100 etc.
To change the preset 100 value, hit the middle button under the display. Then you can hit the right button under the display to go above 100% or the left button to go below 100%. Once you have the setting where you want, hit the middle button agian. Then move on to the other 12 points and do the same.
You will obviously be moving your settings down, but how far will bepend on your long term fuel trims. These, you will want to get as close to 128 as possible.
Once you have finished setting all the positions, hit the edit button agian and it should stop flashing.
One of the great advantages of the afc is you have the ability to tune on the fly. I wired mine in the cabin, taping into the pcm, so I didn't have to pop the hood every time I wanted to change a setting.