What I am trying to say is that the ECM is fed data from various sensors in order for it to calculate the running state of the engine. It has a MAF, MAP, barometric pressure sensor, temperature sensor, O2 sensor, etc. All of these work in conjuction in some form or fashion enabling the ECM to calculate data in realtime and to autocorrect when running in closed loop faster than you would ever be able to notice. For example, if you had a datalogger and external fuel pressure regulator, you would never see a difference in the AFRs when quickly changing the fuel pressure from say 30 to 60 PSI. On the datalog file, you would not even see a blip of a change in the AFR.
The ECM can auto compensate for a number of things based upon the data that it is fed from the various sensors. The only thing that has yet to be said is the range extent for timing and other things that the ECM can deal with verses what it cannot deal with. Know what I mean?
