Intakes just arrived today and I'm about halfway done installing. I noticed on the passenger side intake there are two holes in the side. I know the top one gets a hose attached to it, but there's a lower threaded one that I can't figure out what goes in it. I bought these used so maybe I'm missing something? Looking at pics it doesn't look like others have the threaded hole? I'll try to include a pic here.

I put a bolt in there for now but any insight would be appreciated.

 

Lol, is this a new version of the gen 3? I helped a friend install his last year, and it didnt have that bit.
Even their official image doesnt have that. Is it possible the person you got it from added that bit and had some sort of sensor in there?

 

Yeah I'm not sure I messaged him about it but figured I'd get a reply here faster. The plugs I'm using should work but I'd like to keep the air flow as smooth as possible if I can.

 

Thats custom probably for nitrous

 

PNW was correct. Thanks all. Plugged them and we're good to go.