Explorer 2WD V6-245 4.0L SOHC VIN E EFI (1997)
EGR Tube: Description and Operation
Orifice Tube Assembly
PURPOSE
The orifice tube assembly is a section of tubing connecting the exhaust system to the intake manifold.
OPERATION
The assembly provides the flow path for the Exhaust Gas Recirculation (EGR) to the intake manifold and also contains the metering orifice and
two pressure pick-up tubes.
The internal metering orifice creates a measurable pressure drop across the Hi and Low hoses as the EGR valve opens and closes.
The pressure differential across the orifice is picked by the Differential Pressure Feedback (DPFE) sensor which provides feedback to the
Powertrain Control Module (PCM).
CONSTRUCTION
The orifice tube contains the metering orifice and two pressure pick-up tubes.
