[W37V]

Four days ago, I installed K&N filter. Shortly afterwards car starts being somewhat hesitant (jerky) when accelerating and not giving me full power.

In order to troubleshoot the issue, I start with what I touched since the car run fine. I take out my airbox, and what do I find? I freaking pool of red oil from the damn filter. It took me two paper towel sheets to get all oil out from the box. Paper towel sheets were completely soaked.

I pulled codes with BMWhat app and get following:
Engine / Motor
Fehler: Fuel mixture control 2 / Charge air temperature sensor
Code: 29E1
Fehler: Air-mass system / Air-mass system error / internal Fault
Code: 2D06

Freak me!

I tried to clean it with MAF cleaner, but it does not seem like it did anything. I thing I my MAF is done. At this point I am so pissed at K&N that I will NEVER use their product again. If you are considering getting K&N (and have carbon filter delete) - DON'T!

Is there any possibility of recovery/ fixing the maf before I shell out ~$300 for new one? If the new one is the only option, any recommendations for where to get it? (autozone is selling one for $160 (org. 200 - 20% discount).
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EDIT: So, I cleaned my MAF. I didn't really care about damaging it since I was planning on buying a new one, so I ended up using an entire can of MAF cleaner. I let sensor soak for a bit. Dried it, did it again. Scraped grim off the tiny wires and off the bottom metal plate with a screw driver. Sprayed it some more and installed it back into the vehicle. Cleared codes and guess what? It seems to be working. Codes haven't returned yet. I put about 800 miles since, and car is still pulling strongly with no codes.

TL;DR: Cleaning maf worked.

[timothy2001]

There has to be more to this as I have seen nothing but rave reviews for K&N Filters and am seriously considering them instead of a performance intake.

I am sure others will chime in........sorry to hear about this though.

[W37V]

If you do get it, take it out of the box, wrap it in paper towels, slant it, and leave it like that for 2-3 days, so it freakin' oil can drip out. Those things are SOAKED even thou they might not appear as such when you first take it out of the box.

Also, I did quick search and Amazon reviews are saying same thing what I experienced. I just wish I did more research before.

[OnlyDriveGerman]

I've never had a problem with K&N, specially in a stock air box. I agree and unfortunately think you have a larger problem. Good luck.

[cotmfk]

I also have never had a problem with K&N... I've had their filters on many of my cars. After I clean the filters, I do let them sit for a few hours before reinstall though.

[Delta0311]

Originally Posted by timothy2001

There has to be more to this as I have seen nothing but rave reviews for K&N Filters and am seriously considering them instead of a performance intake.

I am sure others will chime in........sorry to hear about this though.

They are good for the fact that they will pretty much last the life of the car, you just have to clean and re-oil them every once in a while.

Performance wise = no gains

[Get lit]

Originally Posted by W37V

Four days ago, I installed K&N filter. Shortly afterwards car starts being somewhat hesitant (jerky) when accelerating and not giving me full power.

In order to troubleshoot the issue, I start with what I touched since the car run fine. I take out my airbox, and what do I find? I freaking pool of red oil from the damn filter. It took me two paper towel sheets to get all oil out from the box. Paper towel sheets were completely soaked.

I pulled codes with BMWhat app and get following:
Engine / Motor
Fehler: Fuel mixture control 2 / Charge air temperature sensor
Code: 29E1
Fehler: Air-mass system / Air-mass system error / internal Fault
Code: 2D06

Freak me!

I tried to clean it with MAF cleaner, but it does not seem like it did anything. I thing I my MAF is done. At this point I am so pissed at K&N that I will NEVER use their product again. If you are considering getting K&N (and have carbon filter delete) - DON'T!

Is there any possibility of recovery/ fixing the maf before I shell out ~$300 for new one? If the new one is the only option, any recommendations for where to get it? (autozone is selling one for $160 (org. 200 - 20% discount).

Have you contacted k&n about this? I've always run k&n filters and never any issues with them. If the filter did cause a problem from excessive oil k&n should stand behind their product!! I would definately call and complain about your issue and they may cover any failed parts if it has been determined that it was definately the issue!

[Tom Droze]

I'm going to ask the obvious question, did you purchase the K&N filter new, and if so, was it from an authorized K&N dealer? If not, you're likely out of luck with respect to a claim with K&N.

[brewnami]

I am assuming you didn't get these brand new? I come from 10 years in an Audi and people always complained that the oil in the filters can gunk up the MAF, but certainly not from a brand new K&N filter. Perhaps they were not cleaned and oil properly because they shouldn't be wet to the touch. I ran them for probably 5 years in an A4 and an S4 with no problems.

[norsairius]

Something to try post-cleaning with an oiled filter is to put it in a pillowcase and flail it about a bit. Get some air flowing through it by doing that and some of the excess oil (if any) is bound to come off.

[ThatRWD]

Any chance you can post pictures I've never seen this, I put one in my car not too long ago w/o any problems.

[W37V]

Originally Posted by Tom Droze

I'm going to ask the obvious question, did you purchase the K&N filter new, and if so, was it from an authorized K&N dealer? If not, you're likely out of luck with respect to a claim with K&N.

Got it from Autozone brand new (special order for $55) - they are listed as authorized retailer. Figured since BMW one was ~$30, why not spend a bit more to get it - big mistake.

Originally Posted by brewnami

I am assuming you didn't get these brand new? I come from 10 years in an Audi and people always complained that the oil in the filters can gunk up the MAF, but certainly not from a brand new K&N filter. Perhaps they were not cleaned and oil properly because they shouldn't be wet to the touch. I ran them for probably 5 years in an A4 and an S4 with no problems.

You are assuming wrong. Some things are never worth getting used - ie filter.

[rick100]

is there a possibility you did not installed it correctly ... The only complained I read about them was that there was not performance gain although some people swear there is ...

[W37V]

Originally Posted by ThatRWD

Any chance you can post pictures I've never seen this, I put one in my car not too long ago w/o any problems.

I didn't take any when I removed it initially - I wish I did. I will remove airbox again in hopes that I can "clean" maf and see if there is any more accumulation. If there is, I will post pictures.

[jwalker87]

Strange. I've had k&n drop-in filters on most of my cars with zero issues.

[W37V]

Originally Posted by rick100

is there a possibility you did not installed it correctly ... The only complained I read about them was that there was not performance gain although some people swear there is ...

There is only one way to install it. Almost impossible to fk up. Performance wise - if there is, it is not noticeable. It does sound a bit louder. What really opened it up was removal of carbon filer.

[Delta0311]

Originally Posted by W37V

There is only one way to install it. Almost impossible to fk up. Performance wise - if there is, it is not noticeable. It does sound a bit louder. What really opened it up was removal of carbon filer.

I was going to say that.. Just remove the carbon filter, there is really no need for a K&N.

[shadow191]

If you drive a 335 like your sig says, it's not something to worry about. N54's run MAP sensors, not MAF so they're not as sensitive to oil. I've heard of issues on too much oil messing up MAF sensors on lots of cars, but usually that's when someone cleans and re-oils with too much. I've run oiled filters on MAF cars for over 15 years now without issues, but MAF's are sensitive.

That would be terrible quality control if K&N shipped a filter with enough oil to leave a puddle though.

Originally Posted by ThatRWD

Any chance you can post pictures I've never seen this, I put one in my car not too long ago w/o any problems.

[Tom Droze]

Was there any oil on the plastic wrap when you pulled the air cleaner out of the box before installing it?

[ccraig13]

Been running my K&N in the stock air box for 3 years with no problems. I clean and oil it once a year. I wonder if I should just go back to paper though and/or try the carbon delete.

[Tom Droze]

Here is another likely scenario, the filter you installed was previously used. Was the plastic wrap around the filter completely sealed when you pulled it out of the box? AutoZone like several other retailers have a pretty liberal return policy and an unsuspecting counter guy, thinking the filter was unused, sent it back to their DC or a local hub store to be resold. I once found a used oil filter in the box on the shelf waiting to be sold.

[W37V]

Originally Posted by Tom Droze

Here is another likely scenario, the filter you installed was previously used. Was the plastic wrap around the filter completely sealed when you pulled it out of the box? AutoZone like several other retailers have a pretty liberal return policy and an unsuspecting counter guy, thinking the filter was unused, sent it back to their DC or a local hub store to be resold. I once found a used oil filter in the box on the shelf waiting to be sold.

I understand.

However, it was in completely sealed plastic wrap. I tore it up. Unless they opened it, reconditioned it, put it back in, and sealed it, it was brand new.