K&N oil fouled my O2 sensor

[tigeo]

BTW, the correct filter is an AFE dry. No oil to mess with.

Or use a K&N and read the directions.

 

[Jovian]

Have used K&N filters on my last few cars and never had an issue. You just need to follow the directions and properly dry the filter before reinstalling.

Even my MK5 which had a MAF that was very susceptible to oil fouling it up never had an issue with the 155k miles I ran it. Current MK7 has 97k miles.

Now I totally understand not wanting to deal with the cleaning processes which I suggest the AFE dry as others have mentioned.

 

[golfdave]

I have used K&N, Greencotton, & now on ITG (VWR).....I always apply several coast to build up the amount, & never just slosh it on...also leave to stand overnight in a warm place & on a load of newspaper...then next day wipe off surplus….

However you can't do that with the ITG as the thicker grade "road" oil dries to form a dry tacky film....so you to be careful when applying it!

 

[jonatj]

I’ll look at a dry AFe. At first I followed the oiling directions by oiling the side facing up (outside air). But it didn’t have a uniform red color when it dried, so I ran a bead of oil along every pleat, inside and out. There was other stuff going on and it started pouring rain so I wanted to put the car back together quickly. In my rush, I didn’t wipe the excess off or even check if it dried. I had to do an errand and within 20 minutes on the road the check engine light came on. I didn’t put 2 and 2 together until the following day when I could break out the odb2 diagnostics. I drove it to work every day last week with the engine light on. I tried clearing it on a couple of occasions hoping that it would burn off. But not until I ran it with the CatClean did it clear. I’m no shill for them, just telling my story. I messed up and that’s what seemed to work for me.

 

[jimlloyd40]

I’ll look at a dry AFe. At first I followed the oiling directions by oiling the side facing up (outside air). But it didn’t have a uniform red color when it dried, so I ran a bead of oil along every pleat, inside and out. There was other stuff going on and it started pouring rain so I wanted to put the car back together quickly. In my rush, I didn’t wipe the excess off or even check if it dried. I had to do an errand and within 20 minutes on the road the check engine light came on. I didn’t put 2 and 2 together until the following day when I could break out the odb2 diagnostics. I drove it to work every day last week with the engine light on. I tried clearing it on a couple of occasions hoping that it would burn off. But not until I ran it with the CatClean did it clear. I’m no shill for them, just telling my story. I messed up and that’s what seemed to work for me.

I used to have K&N filters and got tired of the cleaning and got the dry AFe and am really happy I did.

 

[SouthFL_Mk7.5]

The rumor used to be that Over oiled K&N Filters ruined MAF sensors. Never heard of them ruining O2 Sensors!

 

[tigeo]

The service interval on a K&N is 50K miles so while I get some don't want to service it, that's only about every 3 years for most folks. I keep my OE filter and toss it in for that service so I can let the filter dry both after washing and after oiling per their instructions - you need v. little oil. K&Ns get such a bad rap but so many use them with zero issue (I have them on all my cars, 2/3 have MAFs). The fouling of the MAF thing is somewhat urban legend - so you have a MAFS that fails, oh you have a K&N? See, K&Ns foul MAFSs! MAFSs just fail sometimes (had 2 go on my MK4 Jetta). Some great videos on this that show you can't get the oil to come off under normal intake flows: