The MAS

This is the stock airbox with the Mass Airflow Sensor in it. I have played with this stupid thing so many times and it only works right in its stock form. I did smooth the edges a little, though. I know that a 1998 Turbo Eclipse MAS connects right up to the 1995 1.8 Mirage and is 2/3 larger. But you need to fix the air/fuel ratio afterwards. I believe the hole in the air box, below the sensor, is to help with intake resonance, but I don't know how. It does not seem to make a performance difference either way. I have blocked it off with no problems. It may actually help to increase the power at certain RPMs.