- Joined
- January 26, 2004
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- 6,113
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- City, State
- Mechanicsville, Virginia
- Year, Model & Trim Level
- 2004 Acura TL
Fords have an issue with their (Differential Pressure Feedback Exhaust Gas Recirculation [EGR]) DPFE Sensors. The DPFE sensor regulates how much exhaust runs back into the system for emissions reasoning.
Now, this is what it looks like:
If you notice the sensor above it is metal/aluminum. Now metal is a good conductor for heat, so when hot exhaust gas is passed through it, it eventually messes up the insides. This is why a DPFE issue is so frequent.
Ford tried to fix the issue with a plastic DPFE:
They last just as long as the metal ones. The voltage for the sensor (which can be found under Live Data or Data Stream in a scan tool) should be around .55-1 volt at idle. Anything higher and it should be replaced.
If you can graph out engine vaccum and the voltages you're likely to see, it would look similar to this graph:
The most frequent codes with a DPFE sensor issue is a P0401 and/or a P0402. These mean following:
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation Flow Excessive Detected
Now with the scan tool (I used a NGS on my last DPFE situation on a '01 Ranger 3.0L) you can verify your voltage at idle. The voltage I had was a little over 2 volts at idle. And I had the two above codes in the system - with only the 402 code coming on with KOER, but the P0401 was in continous/current codes.
If you unplug the sensor and the voltage reads 5.0 volts - then this means that your circuitry is good and that a sensor is needed.
Hopefully that helps some people.
-Drew
Now, this is what it looks like:
If you notice the sensor above it is metal/aluminum. Now metal is a good conductor for heat, so when hot exhaust gas is passed through it, it eventually messes up the insides. This is why a DPFE issue is so frequent.
Ford tried to fix the issue with a plastic DPFE:
They last just as long as the metal ones. The voltage for the sensor (which can be found under Live Data or Data Stream in a scan tool) should be around .55-1 volt at idle. Anything higher and it should be replaced.
If you can graph out engine vaccum and the voltages you're likely to see, it would look similar to this graph:
The most frequent codes with a DPFE sensor issue is a P0401 and/or a P0402. These mean following:
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation Flow Excessive Detected
Now with the scan tool (I used a NGS on my last DPFE situation on a '01 Ranger 3.0L) you can verify your voltage at idle. The voltage I had was a little over 2 volts at idle. And I had the two above codes in the system - with only the 402 code coming on with KOER, but the P0401 was in continous/current codes.
If you unplug the sensor and the voltage reads 5.0 volts - then this means that your circuitry is good and that a sensor is needed.
Hopefully that helps some people.
-Drew