Now I remember, Karman doesn't use sensor number nor sensor cal, hotwire does.
So to set it up, and per the instructions on
http://www.apexi-usa.com/documentation.asp
1. Set Sensor type to Hotwire2. For both S13 & S14 stock MAFs use sensor no. 5 in & 5 out (use 2 in for Z32 MAF)3. Set sensor cal to 1 in & 1 out4. Num of cylinders to 4 (in some cars it needs to be set to 2 due to the ignition config, I don't know if this is the case with the 240)5. Set throttle to up
Now I believe I ain't forgetting anything.