I own a 2016.5 Mazda CX-5 Grand Touring AWD. About 6 months ago, I installed a HUM by Verizon onboard diagnostic reader, for additional safety while driving the car. A few days ago, I received numerous emails with diagnostic codes; one in particular about the Mass Airflow Sensor. Today I took it to the dealer to run a diagnostic test to assess the problem/s if any. After updating the software and running a diagnostic test, they didn't find anything wrong with the car. However, en route home from the dealer this evening, I continued to receive emails with diagnostic codes, particularly one identifying problems with the Mass Airflow Sensor. At this point, I'm wondering if anyone else has had a problem with the MAF Sensor and if it might be something systemic to Mazda and the CX-5.

 

I would say your HUM is faulty or not calibrated to Mazda's standards. I think i've only ever replaced 1 AFM on a petrol CX-5. Not putting the airbox lid on properly can allow dust, dirt & debris pass the air filter & contaminate the AFM.