Originally Posted by
STRATTON there is an o ring that seals one of the faces.
but thats about it...
stratton.
Sounds like your underestimating a seal on an o-ring. I'm not sure what the max rating is but My injector o-rings seal off 60psi of fuel pressure all by them selves as long as the Injectors are held in place that is. It's the samething here. The circiut board is screwed down on to the housing holding the oring in it's seat. I don't feel air should be getting past that. I would think the oring is important.
As far as metal maf housings go I think it's prefernce. I don't think it's a waste because I got my N62 maf for 7 bucks at pull apart because some jackass tried to pull it off a J30 with out any tools. so he cracked the housing and then left it in the drivers seat. I was thinking about building a metal box for my Maf, to sit it on my IC pipes to clean up the look of the engine bay. So no it's not a waste just prefrence on what you'll spend your money on.