three scenarios foreseen, after buying a non-OEM MAF sensor
 

But, would you try a new (and recommended) non-OEM MAF just to test the possibility that your original OEM MAF might be inaccurate, and might be the cause of the bad air/fuel ratio in the first place?

I sure wouldn't/couldn't rent an OEM MAF just to test with, and I would never "buy" one, test with it, and then return it to the supplier (that's outright theft in my moral code).

So, after Xchemist recommended the $23 non-OEM MAF earlier, I figured it would at least tell me if my Siemens MAF (age unknown) is under-reporting the g/s airflow, and triggerering my lean codes.

• 1) At best, I get a solution, after which I'd buy a new Siemens MAF to use (as soon as I get the $$$ to buy it, and keep the $23 unit as a known-good spare),
• 2) second-place result, with no change or very similar to the lean codes and g/s readings I'm already getting, I've got evidence that my OEM sensor is still OK, and I've got a spare, and
• 3) worst case result, as the $23 MAF shorts out my DME, and the X5 burns to the ground, then I made a mistake and I lost $23 and my X5 (but proved those doubting the reasons to get a cheap sensor to be infallible).

That seems a good plan to me, workingonit - very sound thinking. :thumbup:

And I applaud your "moral code". ;)

Found 1000km used VDO maf for my X5, let's see if this finally fixes lean issue...

I just replaced my MAF a few weeks ago with a Bosch unit from Pelican, I think it was. Wasn't too expensive...$70 maybe? The first one made it 20 years, so that's a pretty good investment if the second one does the same.

My X went into the upholstry shop finally this week to get the headline and a,b and c pillars redone. It was all getting pretty ratty. Best $550 I've spent on the car in a while...not counting the new motor, wheels/tires, lift, suspension parts...and all the rest! But man, its nice to spend some money on creature comfort stuff now after getting the new motor sorted out.

I bought "new" pillars and plastic bits in black off of ebay, and 5 yards of classic black M3-like headliner material from ASC/BMW Fabrics, who is active on this and BimmerForums. While the liner was out yesterday I went back over to the shop and ran RCA cables front to back on the left and right sides for the future sound system upgrade, part two. The left side of the ceiling doesnt have any existing cabling/wires, but the right side does. Hopefully there isn't a lot of juice running through these thin wires that will put static into my future powered sub in the right trunk cubbie. Other than that, just some sweat, a wire snake and lots of swearing later and I had them run and zip tied up.
Original tan:
https://i.postimg.cc/RZ5hWfJn/headliner-brown.jpg

headliner out:
https://i.postimg.cc/rwFbCZ46/headliner-2.jpg

New liner and pillars:
https://i.postimg.cc/bNRWnfsH/headliner-1.jpg

https://i.postimg.cc/dVHfWRRh/headliner-3.jpg

Makes me really want to do the seats now. I saw some pics of a beautiful E34 restomod that had some very cool cloth inserts in the middle of black leather seats. Got me thinking....Graham at BMW Fabrics has some very cool fabrics available, but I'd need to find something that matches tan as I like the tan leather. Also, I'm going to look for sport seats in good condition. I suspect they are hard to find a a decent price, but I like the thought of sport seats. I would imagine 5 series of the same model years would pop right in?

Now I want mine in black. Black interior but gray headliner.

Nice job!

need to pull mine and fix the sunroof, when that happens, headliner will be recovered.

Did the one in my M3 a few years ago, not that bad of a job

cheap MAF runs as good as OEM, or maybe better???
 

Thanks, it's just my way.

I hope it does (but are you being facetious?). I think I'm getting positive results, already, on just two run cycles.

Being retired, on a fixed income (with mounting medical expenses for both myself and the wife, and unexpected septic tank repairs, etc. this past week), I would rather have bought another Siemens MAF, like my maybe original from 2001, for $216 at FCPEuro, but deferred it to later. I could've gotten it a bit cheaper at Amazon (or even a Hella @ $72 or Bremi @ $93, both from Rockauto), but those would've been just substitutes at higher prices for the cheaper one that Xchemist had already tried, with success.

I received the MAF in the mail this afternoon, and installed it, and ran two start/run cycles, observing g/s at various speeds, then compared test data from both (at idle) with another test taken months ago.
Attachment 82177

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Not much difference shown, this early-on, but I felt the new MAF reached higher g/s from 1500rpms-WOT, though I failed to capture the proof on my equipment. It does show higher g/s at idle (though temperature differences may have affected the readings), and for the first time ever, the LTFT's fell by themselves (no action by me) while I watched my Foxwell. Perhaps more run cycles on the road will bring the fuel trims nearer normal? and I won't have to keep searching for vacuum leaks, ad infinitum.

After you have enough informational comparison data, clear emission data. The DME will use long term data and short data to average engine fuel. Starting fresh will be interesting data. Wish I had mine here to give you comparison data. I reset emissions after installing new components. Good luck!

clearing data? the right way vs. my way?
 

How do I clear emission data? I don't believe I've read how, and on my Foxwell NT 510, I don't think I've come across that category, either. Reset adaptations?

If I'm correct about the new MAF reading more accurately, and not skewing the fuel trims towards lean, then shouldn't the fuel trims get back to near normal after awhile?

I found a way to reset the fuel trims to zero, by rapidly/repeatedly unplugging & replugging the MAF connector while the engine's running https://xoutpost.com/1219796-post1.html

Should I try that again, or is your method better?

Foxwell has a reset adaptations function and that's what you should use. It likely is in the service main menu.