How can I tell if I have a bad mass air flow sensor?

Hello: well about the only way to tell is get a service manual and see what the output should be for your particular MAF. With ign on and not cranking some have about 2 volts on the output. If you blow thru the MAF the voltage should climb. These sensors are very sensitive to the slightest air movement. If you check its output and blow thru the sensor you should see the output voltage change. I have no idea where to tell you how to do this because I have no idea what type of MAF you even have
good luck
Darryl.