2000 Chevy Silverado heater connector on firewall

The heater hose connector on the firewall of my 2000 Chevy Silverado Z-71 5.3 L V8 broke off and I need to know how to fix the problem. I have the A/C and heater hose connected at this time. The plastic connector for the heater on the firewall broke, How can I fixed this problem. I have no heat.

Also, My Service Engine Light has come, do you think its related to this problem. If not what kind of emmission problem would cause this. I have no problems, it don't run hot, new plugs and wires. I just need to know how to fix the heater connector hose under the hood.

Thanks
Cynthia Smith