Hi cjb2145,
Just so you know code P1411 represents EGR (exhaust gas recirculation) valve position sensor circuit range/ performance malfunction. Possible causes include:
-EGR Valve Position Sensor
- EGR valve stuck open or closed
- EGR Valve Position Sensor harness is open or shorted
- EGR Valve Position Sensor circuit poor electrical connection
Code P0402 represents EGR flow is excessive. Posible causes include
-EGR volume control valve stuck open
- Faulty EGR volume control valve
- EGR solenoid valve harness is open or shorted
- EGR solenoid valve circuit poor electrical connection
- Faulty EGR temperature sensor and circuit