Barometric Pressure Sensor on 1NZ-FE?

[dbrear]

While playing around with some other diagnostics on a real-time ODB-II scanner, I found a barometric pressure reading. Where is the sensor that's measuring barometric pressure? I've been looking for an hour and I don't see anything in the service manual. How is this value determined?

[SirDigby]

it's going to be part of the MAF sensor most likely. it would be in the intake system, and that is the only sensor...