I have a 93 taurus 3.8L V6 automatic GL. I got a 157 code from a digital ford obd 1 code reader. This code points to a problem with your mass air flow sensor. I found out that you can buy a special cleaner for it and this may solve the problem. So I bought the mass air flow cleaner and cleaned the sensor. I cleared the code from my cars computer and drove my car for a couple of days before I hooked up the code reader again. The 157 code came up again. So how would I test the mass air flow sensor to be sure it is bad and it needs to be replaced? Do you use a voltmeter?