I installed the K&N air filter in 2007, and I can’t remember ever cleaning it. It has only been a few thousand miles, but after 14 years, I figured it was time. I had bought the cleaning kit around the same time, and never included it in the blog.
Following all the instructions, a lot of crud did get cleaned out of the filter!
Costs:
K&N Air Filter Recharger and Cleaning Kit – 16.99