ozusa

Attached is a PDF I have made showing how to remove, clean, and replace the MAF on a 2004 Model Year E320 V6. It is not difficult to do.

starbrite

Nice writeup...thanks. Did you do this just as preventative maintenace or were you having some performance problems?

ozusa

I changed the plugs and air filters and got lean DTC codes afterwards on both banks. There is no misfiring.

So I decided I'd better clean everything up that may effect air and fuel measurement before I worry too much and maybe the codes will go away.

I have since heard on this forum that it is not unusual for the car to need to go through a mixture adaptation cycle after getting new filters. It needs to "understand" the associated improvement in airflow.

But I don't know how to make it do that re-adaptation and after 10 days it still hasn't by itself. I don't have Startac in my toolbox.

So I still have the lean DTCs on both banks and a check engine light. The codes are easy to clear with my reader, but I can't get them to go away and stay away. I do not believe I have any bad parts in the picture. The car is actually running pretty well, with maybe a slowness to change up a gear on a steady throttle.

dfrantz2

Good information on removing the MAS. I used this as a templete to remove an clean the MAS on my 04 CLK 500. The only exception was that it was easier to remove the MAS and then disconnect the elec plug. There was no clearance to disconnect it first.

wclopton

I had to replace my Crankcase Breather Hoses after replacing my valve cover gaskets. This DIY was just what I needed to understand how to remove the MAF Plastic Collar and the MAF (AKA A1120940048 Air Mass Sensor).

1. I left the electrical connectors on.
2. I Used a screwdriver to lever apart the clip to get one part of the clip passed the other. The collar then needs to be opened up quite a lot and removed.

I replaced the following breather hoses:

1. 1120180482OE at Valve Cover
2. 1120180282OE Center Portion
3. 1120180182OE Lower Portion
4. 1120180382OE Upper Portion

dewana421

i don't have a problem with my car but should i go ahead and clean it anyways? and what is a MAF spray? in your writeup you said only to use a MAF spray? where do i get it from?

starbrite

He hasn't been online in 9 months, so don't expect an answer any time soon. He does mention in the pdf that he used CRC brand. Check with an auto parts store if they carry a MAF spray.

A quick Google search shows that it is available : http://www.fcpeuro.com/products/air-...FWho7AodjFMAOQ

He never did follow up and state whether or not he was able to get rid of the codes permanently.

Plutoe

Worry about buying your girlfriend a hot dog and forget the MAF cleaning HS---that's mumbo jumbo!!

adadof2

This was spot on, less than 15 min. And was done. Great photos. Follow the example and you'll be done in no time.

ozusa

For those who have nothing better to do than wonder if I ever got rid of the two DTC codes (that led me to write this DIY in the first place). Yes, I had dislodged a vacuum hose near the front left headlight when I was changing the sparkplugs. I noticed it about a month later and fixed it in seconds, cleared the codes and all was soon fine again.

If you have been waiting for this news for three years, you really need to get out more!

Sadly, my E320 4Matic is now no more. The front universal joint on the driveshaft going forward from the transfer case had a catastrophic failure, took out multiple parts, destroying the transfer case and other things under the hood. It was not economically repairable and is now a parts car at my indie. Happily, I replaced it with an S550 4Matic on Friday. So now I have something to really worry about.)

Happy MAFing.

Maxx Benzz

IF I WANT TO CLEAN THE MAF cant I just spray in to it with it still installed? As long as I unplug the sensor why do I have to remove it to clean it?

Maxx Benzz

definitely an upgrade if you dont count the small fortune to repair half the things on your S class. Nice car though