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Discussion Starter · #1 ·
Throwing this thread out there to generate discussion since I found very few other examples of this (even across other manufacturers) and I thought it may help someone in the future.

So just to get this out of the way, yes, my oiled K&N ultimately resulted in the demise of the MAF. I don't think the oil itself killed it, I think I just cleaned it too thoroughly and probably shorted the circuitry. I had a P0101 a year ago, cleaned my MAF, and it went away for a year. Now that it is back, cleaning will not work, it is dead. I have a replacement on the way and will switch to an AEM dryflow in the future.

For those that do not know, the P0101 is MAF voltage low. I have a scanner and sure enough during driving conditions, it bounces between 0.05g/s and 0.08g/s (obviously much lower than it should be).

The curious thing is both last year and this year when I received this code, I began having strange (and a bit unsettling) transmission issues. If I drive with a light foot and never accelerate hard, no problems besides reduced mpg because of the faulty MAF. But if I floor it to pass someone, every gear change after I do this is rough and I mean extremely rough. Downshifts and upshifts whether in geartronic mode or automatic, ALL of them are harsh. It will remain like this until I turn the car off completely and restart the engine at which point everything goes back to normal.

I saw on a BMW forum that the MAF has more influence on the transmission than I previously thought. The guy there said that if the MAF signal is not believable, the car can actually remove pressure restrictions on the fluid feeding the valve body and so now it's receiving full system pressure all the time, causing harsh shifts. I do not know enough about automatic transmissions to know if this is bologna.

This is more a topic for the guys on here that like to debate this stuff. I want to learn something here. Happy debating! :)
 

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It's likely revisionary logic because the car has no clue how much air is being shoved in. It can guess from AFR/boost/temp/RPM but it won't be accurate. I'd wager it's limp mode or something like it.
 

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Discussion Starter · #3 ·
It sure isn't limp mode. I can still hit full boost but the gear changes are like BANG, BANG, BANG from 1st to 2nd to 3rd. It's almost like the heavy acceleration with faulty MAF signal causes the car to have a stroke.
 

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Exactly what happened to my OEM maf, i had p0101 code come up and i was having rough idle when the maf was connected, i unpluged the maf and the car was running like normal since when you disconnect the maf the ECU will run on stock stored settings. My shifts were not rough as far as i remember, the biggest factor was the rough idle. I bought an aftermarket MAF alternative from Bosch Hyundai and it fixed my issue. What killed my OEM maf is deep cleaning, do not overspray your maf or it will weaken the circuit and cause p0101, check engine came on when i plugged back the maf after spraying it too much with mcleaner.

Let us know if the new maf fixes the rough shifting.
 

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Discussion Starter · #5 ·
What killed my OEM maf is deep cleaning, do not overspray your maf or it will weaken the circuit and cause p0101, check engine came on when i plugged back the maf after spraying it too much with mcleaner.
same here
 

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I got rid of my K&N and switched to OE. The car drove and shifted smoother after that. My indy wasn't suprised when I told him that. Honestly the car is just slightly quieter and that's it

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