So I have a 2005 Subaru Legacy Wgn, with the 2.5 single over head cam.
I got this car about 6 years ago, first thing I did was drop a K&N air filter into it !
Well, sad to say I haven't looked at that filter in years, well I just did , and really not too dirty !
So I have the cleaning and re-oiling kit, been inside my house for years and the cleaner doesn't feel like being pumped out of the bottle.
So here is were the "fun" begins.
I posted on the Ultimate Subaru forum and asked is there another cleaner I can use, got no real answer, but I did get a lot of pushback on the K&N filter, lots of people saying just dump it !
I guess the thought is that when you clean and re-oil it, the chance that you might get oil on the MAF sensor isn't to be fooled with !
I just saw the video below that I found here.
I just watched the video below were this guy is testing filters of different types on a dyno, then real world.
And yes it's a Subaru and yes it's a K&N filter too.
I'm not so much interested in the performance results, but what he says at the bitter end of this video, he talks about the charcoal filter that is there . 
I find the idea ridiculous that the oil from the K&N filter can migrate pass this panel and get to the MAF sensor !
https://www.youtube.com/watch?v=GS69owXpGdY
So if I dump it, then I'm finding that is a sea of options other than good old OEM paper replacements !
UGH!
I got this car about 6 years ago, first thing I did was drop a K&N air filter into it !
Well, sad to say I haven't looked at that filter in years, well I just did , and really not too dirty !
So I have the cleaning and re-oiling kit, been inside my house for years and the cleaner doesn't feel like being pumped out of the bottle.
So here is were the "fun" begins.
I posted on the Ultimate Subaru forum and asked is there another cleaner I can use, got no real answer, but I did get a lot of pushback on the K&N filter, lots of people saying just dump it !
I guess the thought is that when you clean and re-oil it, the chance that you might get oil on the MAF sensor isn't to be fooled with !
I just saw the video below that I found here.
I just watched the video below were this guy is testing filters of different types on a dyno, then real world.
And yes it's a Subaru and yes it's a K&N filter too.
I'm not so much interested in the performance results, but what he says at the bitter end of this video, he talks about the charcoal filter that is there . 
I find the idea ridiculous that the oil from the K&N filter can migrate pass this panel and get to the MAF sensor !
https://www.youtube.com/watch?v=GS69owXpGdY
So if I dump it, then I'm finding that is a sea of options other than good old OEM paper replacements !
UGH!