what air filter would be better k&n or kool blue? for a v4 tacoma

I would suggest using the kool blue. It has a finner mesh and it still gives you more hp, and you can still clean it. The k&n filter was designed for baja racers. Their engines are rebuilt so many times that it doesn't really mater that those little particles get in. k&n lets those smaller particles in.

AMSOIL and TRD (A&E) are really good filters also.