[b3lha]

In the stock ECU, code 23 (MAF error) is generated when the ECU receives 2 or more consecutive readings that are less than 0.35% or greater than 99.88% of the maximum theoretical airflow. These limits correspond to about 0.098 volts and 4.756 volts respectively.

The relationship between the MAF voltage and the airflow can be seen on this graph:


As Trevor said, it is directly proportional at the upper end of the scale.

If the ECU detects a MAF error it will try to guess the airflow from the TPS and RPM. If I unplug the MAF on my car it does run, but it runs like crap.

I pulled this information from my JDM ECU, but the USDM graph is only very slightly different. If your ROM has been modified your ROM to accomodate a different MAF then these settings may have been changed.