Help 1999-ML430 Mass Air Sensor
 

What does the Mass Air Flow Sensor do??? What would be a good price for a Sensor. After installing a new sensor would it be necesary for the MB dealer to make any adjustments to the Sensor???? Any help would be appreciated... Jim

The sensor tells the ECU how much air the engine is ingesting so that it may meter the proper amount of fuel. Very critical to engine performance as the engine only operates well over a small range of air to fuel ratios. It is a several hundred dollar part and proper install includes checking and replacing questionable air filters, air box sealing rings, as well as resetting the ECU's adaptations to the previous failed sensor.

Take a look at this post:

http://www.peachparts.com/shopforum/showthread.php?t=231959

Carberated cars use the Venturi effect. The air flow would suck in fuel as it went through the carberator. With electronic fuel injection you no longer have this automatic way of mixing fuel and so you need some way for the computer to figure out how much fuel to inject. For the best fuel economy the method is to measure how much air is flowing in and adjust the fuel accordingly. The Mass Air Flow sensor measures the air flow.

The replacement process is dirt simple, less than 15 minutes if you don't know what you are doing. There are no adjustments afterwards. The sensor is pretty cheap, about US$150 IIRC.