Where is the mass air flow sensor on my 1999 SLK 230 and how difficult is it to change?

 

under the hoood in front of the engine driver side. just follow the black tube down to it. theres a large 5 or 6 pin connector plugged into it. make sure that if you remove the airmass sensor you check it for oil in there. common problem on your car with oil in the intercooler then into the air mass sensor.

 

If there is oil in the intercooler what problems can that cause?

 

There is oil in it, you are right.

 

1st thing is the oil seperator on the top of the engine needs replacement. its on the top of the valve cover. black round type thing with hoses coming off it. that needs replacement and replace the hoses too. and then you should remove the intercooler and drain and clean out the oil. and then clean or replace the airmass.

 

Thank oyu very much