DPFE Sensor Downstream Hose Off or Plugged
2005-2011 Mercury Mariner 3.0L V6
Description
The DPFE sensor downstream hose is disconnected or plugged. This prevents the sensor from measuring exhaust pressure after the EGR orifice, making accurate EGR flow measurement impossible.
Symptoms
- Check Engine Light
- Poor EGR control
- Rough idle
- Failed emissions
- Stalling
Common Causes
- Disconnected downstream DPFE hose
- Plugged downstream DPFE hose
- Cracked hose
- Carbon buildup in EGR passages
- Faulty DPFE sensor
Diagnostic Steps
- Inspect downstream DPFE hose (hose closer to EGR valve)
- Check for blockage
- Replace deteriorated hose
- Clean EGR passages with EGR cleaner
- Test DPFE sensor
Repair Notes
Reconnect or replace DPFE downstream hose. Clean EGR system. Replace DPFE sensor if needed.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1406 on Other Vehicles
Common Questions
What does code P1406 mean on a 2005-2011 Mercury Mariner?
P1406 stands for "DPFE Sensor Downstream Hose Off or Plugged". The DPFE sensor downstream hose is disconnected or plugged. This prevents the sensor from measuring exhaust pressure after the EGR orifice, making accurate EGR flow measurement impossible.
What are the symptoms of P1406 on a Mercury Mariner?
Common symptoms of P1406 include: Check Engine Light, Poor EGR control, Rough idle, Failed emissions, Stalling.
What causes P1406 on a 2005-2011 Mercury Mariner?
Common causes of P1406 include: Disconnected downstream DPFE hose, Plugged downstream DPFE hose, Cracked hose, Carbon buildup in EGR passages, Faulty DPFE sensor.