From DsmWiki

This page is dedicated to information on the DSM MAF system.

The DSM MAF system is a Karman Vortex type sensor. The honeycomb on the front end of the sensor is used to set up a laminar (smooth, with no turbulence) air stream, which is then broken by the bow of the vertical bar in the air path. When the air stream is broken it creates turbulence in the stream (somewhat similar to a boats wake, but more swirly) that is detected as spikes and troughs in pressure by the sensor located on the back side of the bar (bow). The turbulence is then interpreted and sent through to the engine management computer as a square wave form which is interpreted to calculate the mass of air passing the sensor.

Cutting out the big contiguous section of the honeycomb can cause serious issues as a result of the air flow not being made laminar. This means that the air flow will already be some degree of turbulent when it enters the system which will make inaccurate readings as it passes the sensor that detects the turbulence set up by the bar (bow).