Any vacuum leak or tune up issue will typically cause these symptoms. That'* the easy way to spot tune up or lack of maintenance items. High load at low rpms.
A maybe easier way to check for vacuum leaks is to spray vacuum lines with throttle body cleaner while the engine is running. Any leaks pull in the spray and alter the engine sound.
As for maf cleaning. It'* been found that the old method of using q tips has the potential to hurt the maf sensor more frequently than using a aerosol of maf cleaner and spraying the sensor. Reason being is the small filaments Mike had mentioned can be damaged easily and if any piece of the q tip stays on the sensor it will damage it or throw off the measurements.