The working end of the Super's emission control system is this plastic "expansion chamber" located under the cowl. Fuel fumes flows up into this tube when it expands from the tank. It then condenses and flows back into the tank. As well, a line forces expelled fumes to the rear of the car and into a charcoal canister under the right rear fender. This whole thing is supposed to stop fuel vapor and fumes from escaping into the atmosphere. To be correct, we'll have to get this working again.