Both sides or just dirty side???? I read all the posts on stock filter being the best, but the K&N was given to me, and I want to play around with it.
Thanx
2004.5 LLY

You can buy kits to clean and oil K&N's. They are cheap and do not to bad of a job. But you only oil the dirty side.

If you oil the inside or over oil the filter you stand a very good chance of setting a code on your MAF sensor and possible ruining it. Only needs to be lightly oiled on the outside.