mass airflow wireing

ok, hears the deal, if i have sensoer pluged in, car idels at 2000 if i unhook it it idels normal it has done this on 3 diffrent maf sensors, so im thinking the wires? it has 12 volts goin to it and a 5.0 signal volt but how do i ground test it? its only the barometric air pressure code that gets thrown