Question

What is dispenced from the green pump and must be used if a has a catalystic converter ?

Answer 1

Pollutant gases are made of harmful molecules, but those molecules are made from relatively harmless atoms. So if we could find a way of splitting up the molecules after they leave a car's engine and before they get pumped out into the air, we could crack the problem of pollution. That's the job that a catalytic converter does.