Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance p0401 problem

my check engine light was on so i got it checked at autozone and got code p0401. the egr valve seems to work ,i did the vacum hose test. i checked the egr passages at the valve and the throttle body. what else can it be? i had reset the ecu after checking the stuff and drove for like a half hour and got no check engine light. than i turned the car off started it back up and in a little while it came back on. any suggestions. is there a way to test the DPFE ?

although I had the problem with P0402 the information here should be helpful. somewhere in the thread there is a test outlined. try those steps and if it all check then it is most likely the DPFE sensor, and luckly it isn't to expensive i think

I had recurring 401 code. Even though my EGR seemed okay, I changed it anyway, and cured the problem. Took it apart and found that the diaphram had some very tiny pinholes in it. It's easy enough to replace, and not that expensive ($50.00?).

P0401 is an Insufficient EGR Flow code. The most common cause of this is the blockage of the EGR passages behind the throttle body with gook. It's a pretty easy job to remove the TB and clean out the passages - just make sure you purchase a new TB gasket first, and make sure you plug the intake so junk doesn't get in there.

If you do a search on P0401 over all forums and all dates, you'll get some more detailed procedures.

- Mike

i checked the passages and it was only partially blocked on the tb side but not on the egr side and the cel didnt go away. i put a piece of hose on the egr vacum diaphram and sucked on it and the car started to stumble. i plugged the hole with my tongue and it kept stumbling so im guessing its the dpfe. my warranty should cover it, it just doesnt cover the egr valve itself.

If it's under warranty, then there's no loss in getting the DPFE changed.

However, if this doesn't solve the problem, then I'd check the EGR passages. They are located *behind* the TB gasket, and are located on the intake manifold (not on the TB itself). You need to removed the TB and gasket to even see them - they are three channels etched into the intake manifold. When they get clogged, it's sometimes hard to even tell that there are passages there! Once you remove the TB, you'll need a new gasket (~$2.00). If they're plugged, clean them out, install a new gasket, and make sure you disconnect the battery to clear the code. You should then be all set.

Good luck!

- Mike

Here is a post going on right now on General from Todras about the same problem:

P0401 FYI

i think i did mention that the passages are cleared out, and the egr valve itself has been tetsed and working fine.

well i got it fixed and it was the dpfe. i took it to the deaker since iu have the warranty. they still wanted to do a diagnostic after i told them tht i checked everythink else. i was there from liek 8 in the morning till 12 just for one sensor they didnt even want to bother with what i had to say as if i didnt know what i was talking about. than they tried to get me to pay for all kinda maintenance stuff after i told them i can take care of it on my own. i didnt mind the waiting but the service adviser got on my nerves( but she was fine)! but hey atleast i didnt have to pay for a new sensor out of my pocket.