Mass air flow sensor

[laksa]

Can anyone tell me if there is a way to ascertain if the Mass air flow sensor needs to be replaced? What exactly does it do? Anyone got any pictures of a
Mass air flow sensor?

Thanks

Laksa

[sokoloff]

It will throw a check engine light and the code will tell you it's the MAS, P0100 I think.

Len

[BiGbOdYbEnZ430]

yeah...it will a throw a check engine light. i had the same problem not too long ago. replaced the MAS and reset the code. all-set. good as new.

[Kajtek1]

Maybe newer models have a code for MAF sensor, but not our 98/99 models.
With bad sensor you have several codes displaying fuel trim and misfiring. Our 99 ML320 had 10 errors when that happened and still run OK.
Seems that there is explosion of MAF failure lately. Each section has several topics. I think the most detailed I've seen is in 163 section, that shares the same engines.
MAF measure the flow of air by comparing heated wire temperatures and adjust the fuel accordingly. The wires get dirty over the years and give false readings, costing lower economy.
Replacing MAF and spark plugs gave me 15% higher mileage on my wagon.

[BiGbOdYbEnZ430]

it should be the same code for 99-o2 models. it showed up as a fuel trim code. i tried cleaning the MAS, but it was still giving me the same code. so i changed it instead, an no more check engine light.

[sokoloff]

My '99 threw a P0100 code which is the MAF code. I just cleaned mine and all seems well again. It's only been a month, so I'm not banking on being totally in the clear yet.

Len