In this test tutorial, I'll show you how to test the Mass Air Flow Sensor to see if it's bad (and lighting up the check engine light) or not. This MAF Test is done in 3 easy steps. All you'll need, to test the MAF Sensor (with this tutorial) is a Multimeter that can read Hertz Frequency (if you don't have one, I've made a recommendation on where you can buy a reasonably priced one below). In case this isn't the MAF Sensor article you're needing, there are several more I've written and you can find some of them here: