Mass Air Flow (MAF) faulty code
 

It's for my E46 (2001 3-series), but I know this applies to all bimmers. I hope someone can help.

I have a code P0102 coming up, which is MAF or Volume Air Flow.
At the shop they told me to replace the whole box, but is that really necessary if there is a possibility to maybe clean it, check the wires, replace the sensor or the air intake boot/path?
Questions:
- Where is the MAF located?
- Where is its sensor? can the sensor be purchased at a reg parts store or is it an OEM part only?
- How do I check for leaks near the sensor?
- What's the voltage supposed to be of the MAF sensor? so I can check if it's what it should be currently.
- If I purchase the part, is it fairly easy to replace it myself or do I need a mechanic to do it?

Thanks for all the input.

Maf is attached to your airbox.Its easy to replace but you must buy an OE(Bmw) MAF ,as it maybe need BMW coding ,which means that if you dont code it ,the ECM/ECU wont even recognize that you replaced it!
To check for air leaks,simply confirm the intake pipe amd jubilee clips are tighten and also the large "o" rings of the MAF are in place and good.

Do I need to go to BMW for coding or can I get one of those OBDII from Auto Zone to clear it?

Replace MAF and any OBD code reader will clear it. Fyi, that applies to ant of he "P" codes (power train) as standardized OBD ii code.

Suggest that before you buy through a dealer, you check with a local Carquest store. I don't advocate a generic, but in the case of most of the engine electronics, these are mostly Bosch parts. And, Bosch parts in the exact correct part #s needed are available though CarQuest at a great price. Is not a "copy."

In my case, the dealer wanted something like $400 for a MAF. Exact same part number, Bosch part, correct part #, etc. was about $160 or something at the quest.

Any scanner will read and clear codes,but only BMW diag sw ,will code.
So you will need to buy a MAF with a reference that your DME/ECU will code.
Yours being a USA model,you maybe be lucky and no coding necessary!

I had codes P1159 & P1161 come up a while back. Turned out that two Oil Seperator Hoses on top of the engine (had to remove plastic cover to view & access) had disintegrated and were causing a major vacuum leak. I've been told this same problem can sometimes trigger MAF codes instead, or in addition. So, you might want to check, just to eliminate the possibility, before springing for new a MAF. There are posts on this site about those hoses. They have oil vapors flowing through them, which I think contributes to their breakdown and causes them to have to be replaced every few years or so.

Where are those hoses?

Do a search on this site for P1159, P1161. There are a good many posts. If I remember correctly, some have pics. The hoses are right on top of the engine on the V8. Just remove the big plastic cover to get a look. I think there were 4 torx screws holding the cover down, but it may be more. A good idea to get new ones and replace them if they are old, regardless of your MAF situation. If you press on them with your fingers and they feel like jelly or don't readily spring back into shape, they need to go. I found mine just laying there limp with big holes in them.