I'm not sure but I think maybe the AWS solenoid that I broke MONTHS ago (I superglued and RTV'ed the broken part back on) and it's hose might have been causing my vacuum leak? I pulled the hose off while it was running and stuck my finger in the hole just to test it and it seemed to idle a little better (not sure though...). And of course, it died as soon as I let go of my finger...

I didn't even realize it was the freaking AWS solenoid that I broke. If I had realized that I would have capped off that thing ages ago...

...it IS ok to cap it off right? Even the end of that big hose that goes under the manifold?

I suppose it's ironic that they would put a fairly loose hose on the BIGGEST source of vacuum on the whole engine (yes, bigger than the brake booster, at least in terms of the width of the nipple), and then make the solenoid nipple out of incredibly fragile plastic (actually I didn't break it, a friend did). It just about pulls enough vacuum to suck the guts out of a squirrel...

I never did like AWS anyway...

 

Mazda didn't use "incredibly fragile plastic". All common plastics gets that way after 15+ years of sitting in a hot engine bay.

No offence, but I wish people would quit bitching about stuff like this. If Mazda (or any manufacturer) decided to build a car that could last 30 years with no failures at all it would've cost twice as much and never been made.

Yes, you can remove it and cap the connections.