I haven't thought much about my PCV valve during my years with my miata. It came with the 323GTX valve when I bought it which sealed well under boost. From what I understand this is the go-to valve and runs ~$20 from FM. Plastic Mazda valve.

So the other day while running all of it, my plastic PCV cracked into two pieces. I found this metal in-line PCV from Advance Auto for ~$3 and they keep them in stock. Purolator PV1009. Mine looked like this, silver not gold like in advance auto's stock photo:


I tested it with my air compressor to around 20psi and no leaks. Direct replacement for the 323GTX valve, all metal for only $3 and no leaks is a win. I need a 90 degree valve ideally so I also picked up a $6 rubber boot in their 'help' section...that should work well for you 99+ guys with 90° PCV valves.

 

Nice!

 

I bought one of these from Advance last year. The one I bought didn't seal very well under pressure, and didn't flow very well under vacuum. Also, It was really loose in the rubber grommet on the VC. I replaced it with a 323 valve, and it seems much better in all 3 problem areas.

 

im telling you people: run an inline check valve.

 

+1
Works for me with stock PCV valve.

 

This valve may work well as a 1-way valve for the stock MSM catch can return line as well

 

I 3rd the check valve.
Which do you use Brain?

I tried a 3/8" from USPlastics but it has very low flow. So now I'm looking this from McMaster.
I found it on an SRT forum and most seemed satisfied.

Edit: My GTX valve leaked so that's why I'm looking at check valves.

 

I bought a set of 3 medical check valves off ebay for a few bucks. rated to 500°F and worked great.

I ran the stock pcv valve and the check valve and never had issues. there was never a drop of oil in my charge pipes.