Exhaust passages are included in some intake manifolds. Technician A says that the exhaust passages are used for exhaust gas recirculation (EGR) systems. Technician B says that the upper intake is often called the plenum. Which technician is correct?

Question

Quizplus · Accepted Answer

Exhaust passages in some intake manifolds are indeed used for EGR systems, as stated by Technician A. This helps reduce nitrogen oxide emissions by recirculating a portion of an engine's exhaust gas back to the engine cylinders. Technician B is correct as well; the upper part of the intake manifold is often referred to as the plenum. This area distributes air to the various intake ports in the engine.

Exhaust Passages Are Included in Some Intake Manifolds