Code P0401 in my 2001 Expedition

[bar422]

Well today I got a check engine light and checked it with a code a reader to find it is P0401. I have been searching the forum and doing some reading on this and it looks like the EGR sensor is most likely the culprit. What I am wondering is should I replace the EGR valve as well as the EGR sensor? I have 119000 on the truck so I am sure these items have never been replaced. Any input would be great.--Thanks1

 

[Brusky]

Had that same code about a week ago and changed egr valve this last Monday and as of now no code thrown and running great. Just be careful when I bolting valve as I snapped a bolt and couldn't get it out so I had to drill and retap it. 30 min job turned into about 4 hrs. Had to pull entire intake and plentum off. I did however spend about 45 min of that time cleaning plentum and throtle body to like new condition since I had it off.

 

[1997SCEBFEX]

+1 on replacing EGR valve. you're fortunate to have gone this long imho.

PanHandler.

 

[toms89]

May want to check vacuum line to the egr valve and make sure the hoses on the dfpe sensor are good 1st.

 

[bar422]

I picked up the sensor yesterday and am going to install it and check out the hoses today. I will probably drive it and see if the code comes back and if it does do the valve. I think I read other people were having some hesitation issues also.........I am too at lower speeds (it is fairly minor but it is there). I am wondering if this could be part of the low fuel mileage issues too? Any more input would be great!

 

[bar422]

New EGR sensor and hose installed (only needed to replace 1) and I did the Seafoam treatment through the brake booster.........I can tell you that it has ALOT better response when I hit the gas pedal! It also doesn't seem to be working as hard when driving. The white smoke was rolling when I did the Seafoam!!!! I am curious to check gas mileage and see if that increases.....I have a feeling it will.

 

[bar422]

Here is a follow up.......since I changed the EGR sensor and did the seasfoam treatment my mileage has gone up to almost 12.5 so something worked. Thanks for all the input on this!