This is a common topic on here. Many members have found that the K&N cause MAFS fault codes and have since removed them while others have ahd no issues. I would say skip them and do not deal with the hassles they cause for the minimum if any power increase you will get. Hope this helps.
Don't. Over time, the oil from the gauze will contaminate the MAFS. It's really insidious, because sometimes the power only goes away gradually and won't throw off fault codes until they're really bad. The M5 has so much power that if it goes down gradually you can fail to notice quite a bit of HP until it's suddenly restored with new or cleaned up MAFS.
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Need4Spd
'01 M5/UUC SSK + Rogue WSR/RE Tranny Mounts+Royal Purple Synchromax/Axxis ULT Pads/StopTech SS Lines/TC Design from BeastPower Anti-roll Bar Brackets/Dinan LtWtFlywheel and Stage 3 suspension/Goodyear F1 Asymmetrics/Vines thrust arms/IATS relocation/10w-60 oil/hardwired Escort 9500i/Euro Armrest/TEC Cupholder/IceLink/PowerChip 91 Gold/TUBIs!/Strong Strut/BSW Stage 1/BT/Angel iBrights 3.0
'05 M3 Imola Cabrio 6MT, Nav, HK
"Is it the sounds that make a BMW a BMW? A BMW is designed to be heard, felt, experienced. So our engines sing. Our steering talks back. And we insist on offering manual transmissions in nearly all our models for drivers who crave them. The result is an almost telepathic oneness with the car. Just as surely as you can hear a BMW, a BMW hears you."
So even warned, I still installed K&N filters.....just recently with 2k miles of driving I developed hesitation after driving the car on a cold engine.......so I decided to clean the MAF sensors with "Formula 409" using previously posted instructions........and now the car feels new again with a smooth acceleration on all gears.... http://www.walgreens.com/store/produ...&id=prod372197
Here goes my opinion on K&N:
They do allow more air through the filter when new, becuase they dont filter as good as paper! Its real simple, they filter less that your OEM filter, allowing particles to enter your cylinders.
Then when they get dirty, they allow LESS air to pass than a paper filter with the same mileage.
Any K&N users, look at the inside of your intake tubes when you take a dirty K&N off. Look at all the silt stuck to the side of your intake tubes, thats the stuff getting by the filter.
Linear Mode
