Exhaust Gas Recirculation (EGR)

1. Powertrain Control Module (PCM)
2. Throttle Position (TP) sensor
3. Mass Air Flow (MAF) sensor
4. Intake Air Temperature (IAT) sensor
5. Idle Air Control (IAC) valve
6. Engine Coolant Temperature (ECT) sensor
7. Heated Oxygen Sensor (HO2S)
8. Camshaft Position (CMP) sensor
9. Knock Sensor (KS)
10. Vehicle Speed Sensor (VSS)
11. Crankshaft Position (CKP) sensor
12. Fuel Injector
13. Coolant Temperature Sensor (CTS)
14. Exhaust Gas Recirculation (EGR)
15. Manifold Absolute Pressure (MAP)

Source: FreeAutoMechanic.com/car-engine-sensors.html

Exhaust Gas Recirculation (EGR)

Recirculates a measured amount of exhaust gas into the engine's air intake to lower combustion temperatures and reduce emissions, especially NOx.

EGR Valve Position Sensor

The EGR valve position sensor is a potentiometer that monitors the movement of the EGR valve pintle. The EGR valve position sensor then provides the pintle position to the PCM. The EGR valve position sensor signal varies from approximately 0.50V when the valve is closed to approximately 4.5V when the valve is open.