I'm in the middle of putting together an LSVTEC. I'm going to be running a 3-port breather setup with 2 to the VC and one to the back of the block -- running it to a fitting on the right side.

I'm wondering what this plug on the left is for. I've seen it with what looked like a sensor screwed in it, but my GSR block didn't have anything like that.

Is this something I need?

 

OBD0 fan switch

youll need to plug it or swap the plugs from your other block.

 

Thanks a lot. I'll be putting one of those big 14mm allen plugs in.