System Components
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The EGR valve controls the amount of exhaust gases introduced into the intake manifold.
The EGR bypass directs exhaust gases straight into the air intake system when the engine is cold during startup to get EGR working as soon as possible to lower NOx levels. At normal operating temperatures and above engine idle speeds the bypass reverts back to normal operation.
The EGR cooler is a floating core design, allowing the EGR coolers to independently move within their housings as they thermally expand and shrink. The EGR cooler also uses both engine and the powertrain secondary cooling systems to maintain EGR temperatures.