Code P0401

COMPLETESUCCESS247

MEMBER
2002 FORD WINDSTAR
3.4L
V6
2WD
AUTOMATIC
155,000 MILES

I bought this van on Facebook and this specific code has been giving me a headache. So far I've change the EGR valve, DPFE Sensor, and the EGR vacuum Solenoid, and still the code comes back.
I've even took apart the intake manifold and cleaned all six ports that can also cause the code to appear. The code came right back after that. The engine runs with a slight miss. But as I continue to drive the vehicle. The slight misfire has faded just a little. What's causing this code to reappear?

1 Reply

BMDOUBLE

MECHANIC
1,139 POSTS

P0401-EGR insufficient flow. Have you made sure that you have a good vacuum supply to the solenoid? The small plastic vacuum tubes have a tendency to snap or even melt shut. It seems as though you've been pretty thorough with the usual suspects, even the intake which gets missed! I would just make sure your vacuum supply is good and your DPFE sensor volts read 1.0 when the EGR is closed and 4-4.5 open.