chaserthedog

I am getting DTC P0401 (Insufficient EGR Flow). I have replaced the DPFE Sensor, the EGR valve, and the EGR vaccum solenoid. The car has been working great for almost 2 days and all of the sudden, the CHECK ENGINE light turned on. I hooked my Actron code reader back up to the car and found the same P0401 error. What should I do now???

1999 Ford Taurus with
Duratec V6 24 Valve DOHC

Thanks,
Neal

tbird100636

Neal, make sure your EGR tube is clean-carbon build-up in the tube can cause this code-clean it with carb cleaner and a long thin brush.

LunaticSVT

A code P0401 most likely means one or more of the following has happened:

1. The DPF (differential pressure) sensor is faulty and needs to be replaced
2. There is a blockage in the EGR (most likely carbon buildup)
3. The EGR valve is faulty
4. The EGR valve may not be opening due to a lack of vaccuum

Possible Solutions: In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.

1. Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's. There should be a noticable difference in RPM's with the EGR open
2. Clean out the EGR valve to remove deposits
3. Replace the DPF sensor
4. Replace the EGR valve

modenaf1

If the EGR is blocked or if it is not opening, are there any adverse effects? Are the emissions increased? A loss of power?

Yfranie

"If the EGR is blocked or if it is not opening, are there any adverse effects? Are the emissions increased? A loss of power?"

Could anyone answer this question? I get the same problem (p0401) with my Taurus 2000. What's the adverse effects if leaving the engine check light on?
Thanks.

LunaticSVT

You may or may not notice any poor performance as a result of a malfunctioning or blocked EGR valve. It would depend on the degree of failure.

The egr during cruising speeds opens allowing exhaust into the intake manifold. The purpose of this is to cool the temperature of the combustion inside the cylinder as the spark plug fires. This in turn, lowers emissions. If it is blocked or unable to open you will see higher emissions.

Depending on your state if you have a CEL displayed or DTCs stored in your ECU during emissions testing you will fail. Again this is on a per state basis and varies. Some of the general symptoms are a rough idle, bad mileage, engine missing at high speed, engine missing under high load and even engine missing with higher temps.

modenaf1

Ok, cool. Thanks a bunch. I have the same error code on a 96 with the Duratec as well.

It didn't start until they put the new transmission in, and since that it seems less powerful, and when I step on the gas I hear a hissing noise from the drivers footwell, almost like a turbo hiss. I think something is messed up with the exhaust.