At idle 1.00v-1.120v is considered normal. WOT can be anything because it's a not linear.
The ecu increases the voltage to make the hot wire give a readable value via the signal line, the ecu then does the math. So you could be pulling anywhere from 4.20v-5.12v at WOT on a z32mafs and not be making 500/600hp that the mafs has been rated for, same can be said for part throttle, other sensors are calculated along with the mafs voltage, so at cruise you are pulling 2.450v your not using 50 percent of the mafs capabilities..
Just a rule, if you happen to be pulling 5.00v or 5.12v on the mafs it's time to upgrade something. I have 3 cars here pulling the same voltage on the same z32mafs and the air/flow percentage is different for each one. I tried to explain it!
