My MAF is reading 5.10 at 6000 rpm in third.

[douglas vincent]

And I have it scaled down via a poteniometer.

So while they are supposedly 0-5 amps scale, do they go higher? I have the aluminium type.

[douglas vincent]

I tried to get it back up to 5.10 again, but the best I could do was 5.04

[free5ty1e]

0-5 volts scale, not amps.

5V = ~350 CFM @ 85*F (unaltered reading)

I believe some WRXs have a MAF with more range.

Readings above 5V are not in the rated range for these sensors, and therefore cannot be trusted or easily repeated.

[vrg3]

Unless you've changed things since we last discussed them, you're not scaling down your signal.... at least, not exactly...

You used the pot as a variable resistor and put it in
series with the signal wire, right?

You understand the difference between amps and volts? And what Ohm's law says?

There are two possible explanations for a signal above 5 volts:

1) The sensor uses its own internal 5-volt reference, and this reference is off by enough to allow it to think 5.1 volts is 5 volts.

2) The sensor intentionally sends a 5.1-volt signal when its range has been exceeded. I do know that when its signal hits the rail, the ECU reports a 5.10-volt signal.

[free5ty1e]

That little extra tenth of a volt is the sensor screaming for help because it can't keep its wire warm