The ME is a purely open loop chip and does not use the o2 sensor for fueling adjustment. One can simply pull the o2 out and plug the hole whenever desired.
The chip is user programmable as explained in the above link.
It comes with established defaults and needs very little tweaking right out of the box. The drivability of this chip is outstanding and the programability allows it to be fine tuned to particular combinations.
You will never know it is open loop unless you have to pass strick emissions' testing and that, it will not do. It was originally made for big injectors but it works well with all the injectors it supports from stock up.