K&N Filter ?

[ZWILD1]

I ran a K&N in my first 91 Z. The car I bought has one in it. I did a filter clean and recharge using the K&N products. Has anyone had issues with the K&N filter oil cause problems with sensors? I did the filter service several months before Carlisle and it hasn't really been driven a lot of miles. But I now have both 02 sensors showing rich. I remember from my first car seeing the red K&N filter oil making it's way up the intake hose and into the air horn and probably into the intake.


When I pulled the assembly to do the filter service it had some oil in the hose and the air horn. I was reading on another car forum where a guy claimed his mechanic said his Mercedes needed lots of work from the filter oil causing problems like issues with the MAS and then other said it was a problem. So I thought I would ask ZR1 guys if any problems from the oil.

[Z51JEFF]

I’ve got the K&N filter and I don’t oil it after it’s cleaned,I don’t drive in dusty areas so it’s no big deal plus it just makes a huge mess trying to clean it.

[32valvZ]

I have one in my 90. I did the recharge and cleaning... the key is to let it dry 100% and LIGHTLY oil it.... I havent had any issues and I didnt see any oil in the intake tube when I had it off a couple weeks back....Im sure I would have seen it too because I have a smooth, white anti-collapse insert in mine...

[Paul Workman]

I have the K and N setup too; came with the car: bought in '07 and I never had a minute of trouble with it. But, it sounds to me like you're using WAAAY too much oil!

I don't know if that (K&N) oil has anything in it that would affect the O2s, but in any case that K&N kit should last for a couple treatments (at least). IOW, you shouldn't have ANY oil collecting in the accordion bridge hose or in the plenum!

Is the K&N oil contaminating the O2s somehow? I couldn't say. But, you can eliminate the excess oil from the intake and see if that fixes the rich problem (before changing out the O2s).