I have just completed cleaning the air mass sensor in my A140, and thought it might be handy if I uploaded some pictures and description of how to do it.
This can cause the engine warning light to go out on its own. I had a bit of trouble getting mine to go out, but managed in the end with Carsoft MB and the OBD cable.
Make sure you have fuel in your car when testing after doing this - I thought I broke my engine, but I had just run the tank dry!
Edit: LINKS ABOVE DO NOT WORK: The guide I made has disappeared, so I have started it again and uploaded the photos with brief descriptions. I will complete it as soon as I can.
At the chance of boring 'A' Class owners ,
there are links on my page 38 which will get you 10% off MAFS repairs , New unit fitted by MB is at present about £1300.00 you can get your unit tested for £35.00 and repaired for about £250.00 plus carriage and VAT you must mention my site to get the 15% discount.
Although there are two companies mentioned only ECU testing repair the ECU portion as well as the MAFS , so if you think you have an ECU problem rather than MAFS it would pay you to sent it to them.
I have no connection with either company and this is a concession to my readers by the managements of the two companies involved.
I have uploaded the pictures to my site - as I have been busy, I will be putting the guide back together from memory over the next few days and putting the descriptions on the web page. The photos are pretty much self explanatry as I will post them in the correct order. You need to be careful when you get removing the cover from the air sensors and when cleaning as you don't want to break them. Carb cleaner worked well on mine with some cotton buds to lightly rub it in. Also take care when removing Torx bolts from circuit board as I nearly scraped all the components off .
MAFS & ECU Repairs 
.
Linear Mode
