Is there supposed to be another vac line connected to the cannister? I just pulled it out, and there is only the feed line that comes from under the fuse cover. I verified the cannister is fed from that line. There is not another hose nipple on the cannister and no other hoses in the vacinity, so there must be another source feeding the HVAC programmer?

Should be connected now, I was careful when replacing the airbox, and watched to make sure it didn't disconnect.

Well I just did some more tracing of vac lines. Tired of working on this thing, just did new front rotors/pads and upstream O2 sensor last night.

Just for future reference/FYI:
The vac line that feeds the programmer for vent control enters the vehicle through the outer firewall port on the passenger side under the maxifuse cover. The vac feed line 'T'* just below the check valve, where the line enters the harness loom (the loom from the firewall). One side goes into the vehicle, the other to the cannister/bottle under the battery.

I have good vac through the check valve, so it looks like I'll likely have to pull the programmer. Seems like the easiest fix is to just cut out the plastic plug and run the vac lines directly into the programmer. I don't think I'll bother with it until the weather gets nicer (like next June!).