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Yes. Excessive oil will foul the MAFs.
 

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First I heard of this was on Rennlist (Porsche) many years ago. I figure if those oil filters really did help generate more horsepower, the cars would come that way from the factory.
 

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And then you have the fine particulate filtering of the K&N's vs. paper.
Sure K&N's flow more but also allow more dirty air through.
There was a post years back where a guy in a miata did this fairly comprehensive filter comparison in an Urban area.
The results were quite surprising. You would think that there would be no issue running K&N in a city environment, but they definately let more dirt through than paper.
Now - this wasn't super scientific, but the pictures were interesting enough.
Then there was another article that put in a bunch of filters during dyno runs.
They found that the gains were pretty insignificant -

That said - many people run K&N with no ill effects. Probably because the particulate size is small enough not to cause any issues.
I have K&N's for the stock OEM filter housings, but run paper when I was having issues chasing horsepower.
I think you don't need to worry about the MAF's if they are properly oiled and allowed to sit before putting into use.

Even with the ALPHA-N - I am hesitant to put these filters in.
I'd prefer to feed the S62 with clean air consistantly. Paper filters are cheap, S62's are not.
 

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Paper filters are so darn cheap...no reason not to spend 30 bucks a year on filters to not even have to worry about fouling the MAFS
 

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Go for AFE Pro Dry S filters. They are oil less but cleanable/reusable and offer a tad more flow over paper filters.
 

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I have always run a K&N in my car with no issues and 185k miles on the odometer. I have a spare K&N filter that I clean, dry and then re-oil. I let it set overnight before swapping it with the dirty one. Oil analysis shows no evidence of dirt getting past the filter.
 

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K&N vs. MAF

what if u have put K&N filters in....... do u need to spray in a cleaner to clean of the oil ? I put in some right out of the box. did I screw up my MAFn sensors ?????????:eek:
 
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