How do I figure out why my car is running so hot?

The mass air flow sensor is also referred to as a MAF. The MAF sensor will not cause a vehicle to "run hot". What specifically are you experiencing? For overheating issues, multiple causes are possible. You could have a base engine issue internally. You could have a coolant flow issue, a cooling fan issue, a thermostat issue, or even an air pocket in the cooling system. Testing will be required to find out what's going on.

More details will help fetch a better answer .. Under what conditions exactly does overheating occur?