The 2004 Sienna uses the 3MZFE motor.
2003 (which I have) was the last year for the 1MZFE in the Sienna
I looked the PCV valve up on Rockauto and at toyotapartszone, and you have a metal one that screws into the REAR valve cover on the passenger side.
If you go to
www.toyotapartszone.com and enter your vehicle information in (I highly recommend you use your VIN when buying parts as it will give you the most correct parts for YOUR vehicle).
Select "Tool/Engine/Fuel"
Then Select "ventilation hose"
Above the actual parts list there will be a "(301-)3MZFE Get-Ino tab Click on that and "open" to get a drawing, which will show the location of the PCV valve in the rear valve cover.
On my 1MZFE motor, which is similar, the PCV valve is kind of hard to see and get at.
If you plan on hanging onto your vehicle....and since you are asking about the PCV valve, you must do some work on your own, I would bookmark that website.
REASON?....they have by FAR the best parts diagrams that I have found anywhere.
Their website is sometimes kind of hard to use to find a specific part, but those drawings are a really big help in locating and knowing you have the CORRECT part because you can reference the drawing to the part.
