2001 4.0 with P0401 egr code

[A. Wayne]

Ok- I quickly checked the vacuum lines going to/from egr sensor, and unplugged line to valve. With the vacuum line unplugged from the valve, I can feel pulses of vacuum coming from the line at an idle. Any thoughts on where to go next? I don't know if the sensor is sending enough vacuum to the valve, or if it is sending vacuum at the right time. I plan on taking the valve off, cleaning it and trying to manually operate it to ensure it isn't siezed. Should I just start throwing parts at the truck? And most imprtantly, how do I clear the code? Just unplug the battery, or do I need a scanner, or can I use a jumper wire betweeen some of the ports on the scanner port on the truck?

 

[Damon Owen]

I have the same error code, low EGR flow. I swapped out the EGR valve and the light came back on. After a couple of days the truck wants to stall out when I shift through neutral. I can feather the throttle and it runs smooth while in neutral. I don't know if I should change out the EGR solenoid and keep working through the EGR system. The neutral stall seems like a vacuum leak kinda deal, but I dunno'. I know lots of folks deal with the PO401 code-any ideas?

 

[Earl43P]

P0401 is almost always the DPFE, very common.


http://www.tomco-inc.com/techinfo.aspx
http://www.tomco-inc.com/Tech_Tips/ttt35.pdf
http://www.tomco-inc.com/Tech_Tips/ttt36.pdf

Another common problem is carbon blocking the EGR ports.
EGR valves rarely fail, solenoids occasionally do, but it is easy to test it. Hold the throttle open and see if it applies vacuum to the valve. It should NOT apply ANY vacuum to the valve at idle, ever.

 

[Thed]

I replaced my whole EGR system before checking to make sure I didn't have any carbon build-up. Bad mistake because it would have saved me a bunch of greenbacks if I did.

Before...

After two cans of throttle body cleaner...

Well now I no I can go for a long ass time without having to worry about my EGR system.

Here's a link to some DPFE sensors... http://www.rockauto.com/catalog/x,carcode,1372711,parttype,5088