Try cleaning it . . check out MENU#4a . .

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Regards . . . . JimF
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'94 S500 Cpe

Visit my Mercedes Web Page

....and check your air filter. too.

Air filter is new. Cleaning the MAF is a good idea but I've heard that the problem usually comes back if only a cleaning is done. I'm doing this for someone and don't want them coming back in a few weeks with same complaint. Have you had experience with cleaning and lasting results. Do you clean with aerosol, such as brake cleaner or do you use a swab and alcohol?

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1972 450SL
1982 300D Turbo

I use CRC MAF cleaner ..aerosol.
Works great and fast/easy to use..

I cleaned the MAF with CRC electrical contact cleaner which is the same formulation as CRC's MAF cleaner. Results were negative. I then tried cleaning it with alcohol on a swab and got modest to no improvement. I replaced the MAF with a new Bosch unit and car is fixed! I'm measuring about 550kg/hr at 4000 RPM, 3rd gear WOT. This is what it should be.

btw, I've "fixed" a few Toyotas throwing lean codes by spraying the MAF but doesn't seem to work as well with these MB Bosch film type MAFs, at least in my limited sample group.

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1972 450SL
1982 300D Turbo

Same here . . in the three or so 'film' type that I've done, they didn't "stay" fixed but cleaning the older hot wire type works perfectly.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I know this is an old thread but I am having an odd issue and want to rule my MAF out as a cause. I have a 02 E55 and I am getting -18% fuel trims (less then 1% difference left to right) with my new MAF module.

I have post my original question in this thread but I am not getting any answers

http://www.peachparts.com/shopforum/showthread.php?t=210103

Thanks

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Eraser-X
06 R350 with sport package
02 E55 Black on Black with most options
91 Range Rover GDE
8X 280TE
53 356 Cab