Engine/Transmission (1998.5 - 2002) how to test for a bad MAP sensor?

[SamBrown]

my buddies 99 24v 4x4 automatic dually has been getting 10 mpg. new lift pump that puts out good pressure, truck is stock with a newly rebuilt transmission. no fuel leaks. i am aiming towards the iat and map but want to know if the map is bad before replacing. what kind of voltages or ohms am i looking for at the sensor?



thanks for the help guys

Sam