Guys,

I could use your help.

Chasing down a P1237 code (upstream flow low input). I found the below valve-thing off of the line from the air intake, and it has an open inlet that does not have anything hooked up--it's just venting to the atmosphere. I assume this is not correct. What line should be connected to this?

 

BUMP


If I had the factory air box, I'd go look for you. Previous owner put on an Alta CAI though.

Someone knows.

 

If you have that line leading FROM the air box, that is the box's vac line for the JCW intake flapper. Flapper is at the back of the box to the cowl and when open allows more air in from 4300 RPM and up, and more supercharger sound to be heard.

Some folks perform what is known as the "flapper delete", to allow more air in all the time. This is done by removing the flap in the back, and disconnecting and sealing the line from the BPV and maybe even disconnecting wiring to the box. Hence the hard plastic hose line from the box you show, would not be hooked up.

IF your JCW air box was wired and had the flapper working, then there may be an unattached vac line hanging in area of left side of engine. Check for a 1/8" vac line and Y splitter off from a plenum from the BPV.

 

Thanks for the input.

The splitter pictured in my original post is the only Y-splitter that I could find in the area. I even plugged the open end of this Y-splitter and ran the car, but still got the p1237 code.

I pulled out the map sensor--looked fine. But that's not to say it's working.