A MAF delete is required (normally on high powered tuned cars with bigger turbo/injector modifications) where the sheer volume of air passing through the MAF housing causes the sensor to hit its maximum operating range and in some cases burn out.

Sometimes the MAF reading hits its maximum value and touches the maximum allowed voltage read by the sensor making a fault code in the ECU which puts the vehicle into a safe mode (limp mode).
A maffless tune involves the use of a manifold absolute pressure (MAP) sensor. The MAP sensor measures pressure in an engine’s inlet manifold. When coupled with RPM data, and a table of volumetric efficiency over the operating range of the engine, the MAP sensor can be used by the engines ECU to calculate fuel requirements.
NOTE: MAF delete options are not suitable for all vehicles. Contact us to find out if this option is available for your Vehicle.