The exhaust gas recirculation (EGR) tube plays a role in limiting the amount of NOx emission released into the atmosphere. It was introduced in 1966 as a way to reduce smog that would flow through the vehicle's exhaust.
EGR tube operationThe EGR system takes unburnt fuel that travels from the exhaust manifold and recirculates the molecules into the intake manifold. The system allows the engine to consume less "new fuel" enhancing the fuel economy and lessening vehicle emissions. The component that transports all the unburnt fuel is the EGR tube.
This system has been utilized since 1973, and today mostly every car uses it. The tube has been designed to last you a very long time, but since they are located in a certain spot and hot exhaust gases travel through it a lot, it can wear out which makes the EGR system impractical.
Common problems with a bad EGR tubeA bad EGR tube can lead to rattling sounds, smog fails, and leaking.