to,
Here is the emission Vacuum Reservoir Can (Tank, also called and labelled as CANNISTER in the pic) (VRESER)
http://i14.photobucket.com/albums/a304/booba5/overhead-2.jpg
pic by Booba
and Smog Pumps Inlet Silencer/Filter Location
for the fuel that wasn't burned in the combustion chamber, we need extra airflow pumped into the exhaust system. This air with the heat of the exhaust creates further break down of HC, CO, and Nox into CO2, H2O, and N2. The catalytic converter can accept all of the airflow without fear of over heating during cruise. We need hot exhaust gasses to help complete combustion and converter operation. Air is pumped into the converter, but will dump to the atmosphere after several minutes to prevent overheating the converter. The converter is cooled by air passing under the vehicle..." Source: by Ryan M