Disconnected Hose Mystery

[asifallasleep]

I have an 83 SC and found this disconnected hose. It runs through the drivers side firewall. I've attached a few pics. I recently failed my smog and noticed a few days later that the previous owner had disconnected the 02 sensor. Fairly common. Smog folks missed that in their visual inspection!! With the sensor plugged in, the car has a high wandering idle from 1200-800 rpms. Car runs great but a little rich, hence the failed smog. Could this disconnected hose be the problem when the sensor is connected? Any ideas what it's for? Also if I plug in the sensor will I pass the smog or in addition will the air/fuel mixture have to be re-adjusted to pass? The blower/ac has been removed from this car. Thanks. (Last photo is of 02 sensor i believe.)









IS THIS THE 02 SENSOR IN THIS PIC BELOW?