I have a 99 RX300. Anybody know where the PCV valve located. Picture or diagram will be helpful. Thank you.

 

It's located right under the intake toward the firewall on the passenger side. If you open the hood and look at the engine, it will be on your left and it's mount on the valve cover (bank 1, toward the fire wall).

 

I have the PCV valve in hand and replace it right away after I read your post. Took less than a minute to replace and locate. Thank you VVT-i.

FYI: PCV valve is the most common preventive car maintenance to forget.