Can't find where tube reconnects to - 93
 

I replaced the thermostat in my 93 RX7, (which required disassembling nearly 1/4 of the engine bay). When I put it all back together, I am left with a hose that I don't know where it originally went.

The hose is the one that comes off the right hand side of the air filter assembly. It has a ] shape. It appears that it would connect to something under the air filter?:scratch:

The car seems to run fine without it, but I get a whistle when running the car. kind of annoying, and it has never done that before...:(

--Edit
I should add that I did remove the entire air filter assembly. I tried to leave all the hoses hanging, but apparently this one came fully off.
I do own a matinee manual, but can't find the air-filter section (if it even has one)

If it's this, it's the hose to nowhere (does not connect to anything).

https://cimg3.ibsrv.net/gimg/www.rx7...0831076fe7.jpg

I'm not sure it's purpose though. Maybe if the filter gets overly clogged, you have some airflow.
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That would be the one. Cool, so I am not insane! Now the question is if thats factory how did I introduce a whistle? (should I create a new thread for this?)

It shouldn't whistle. Try plugging it to see if you still have a whistle. If you do, it's something else

Remember...in stock configuration the blow-off valve empties into the stock air box. That's the vent hose for it. But you're right, it just hangs underneath the box.
Generally a whistle is a coupler leaking somewhere on the intake track under boost.

This is a "Tube to nowhere" in that there is no connection. It is a just vent tube and doesn't connect, just hangs there. Drove me crazy trying to figure it out originally...