BMW 2002 1600 Fuel Expansion Tank. This is a critical part of the enjoyment of your 2002 and the proper operation of the emissions system on late model vehicles. The small hose from the fuel filler neck connects to one port, the second port goes to the engine compartment to dispose of fuel vapors through the emissions system. This tank is in good used condition, no cracking or other problems that make would make it leak fumes into your trunk. This item is required to pass many smog inspections, buy it now to avoid failings your emissions test.