My k&n filter is stained with mud. Can I soak it in water or something to clean it out or will that just ruin it?

 

go to your local autoparts store, and buy the K&N filter cleaning kit. It'll have the instructions on how to clean it. NIce thing about K&N's is you clean them when they get dirty, you just have to re-oil it which is what the cleaning kit is

 

^^x2

Mine was the same way a couple of weeks ago. I just cleaned it with their cleaner, oiled it, and it's good as new.

 

If you would be familiar with how to clean a K&N air filter, you'd know you'd run a hose through it with the cleaning solution, let it dry, then spray on the oil. This question would've been answered for you. lol.