Check Engine Light help (P0401) | Ford Explorer Forums - Serious Explorations

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Check Engine Light help (P0401)

Gse Brent

Well-Known Member
July 9, 2010
Reaction score
City, State
Small Wonder
Year, Model & Trim Level
2001 Explorer Sport Trac
So a couple months ago my check engine light came on and i had it scanned and it threw the code P0401. The people that scanned it said it was the DPFE sensor which i went out and bought and replaced. Still had the code. Had the truck in for an oil change and the tech found a vacuum line with a hole in it. Replaced the line and problem solved. At the present time the light just came back on with the same code. HELP! What could it be now? It runs fine where as not like before when it had a rough idle. Any thoughts?

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Could be a bad EVR. They don't go bad oftern but it does happen. Also I have seen aftermarket DPFE's cause the could to come back, Put a Ford one and then it's all good

I'm not sure if i want to just keep buying parts to get rid of this check engine light or just pay the dealer $75 to fix the problem and tell me what is it.

mine went off also and the code P0401 says it is EGR flow insuffecent. Is this the same? or am I off? and can it be cleaned? Thanks

Do you put a Ford dpfe sensor on it? Aftermarkets don't last long.

I did put the oem ford dpfe sensor back in it, same problem though. Also just replaced the egr valve and the vacuum solenoid. Check engine light came back on.

where was leaking vacume line? i have similar problem . mine also wont rev out (stops at about 2850 rpm). i keep clearing code 401 but caint seem to trace down the problem.

Mine ended up being the dpfe sensor again. This time i bought the oem ford one and haven't had any problems yet.

where was leaking vacume line? i have similar problem . mine also wont rev out (stops at about 2850 rpm). i keep clearing code 401 but caint seem to trace down the problem.

Is yours a Job 1 or 2 2001?

Your Trac has a rev limiter and is designed to NOT rev over 2800-3000 in PARK or NEUTRAL.

my trac was manufactured 10/00 so i think its job2

There are two rubber tubes going from the DPFE sensor to the EGR tube. Remove them from the DPFE and, by whatever means,blow into the hoses/tubes. They should pass air through them and into the EGR tube fairly easily. You may find one of them clogged up. That's what I found on my wife's Mustang. I took a small drill bit in a hand vise and drilled through the carbon build-up, which an ice pick wouldn't penetrate, and the DPFE functioned again and the code went away. :D

i removed both rubber tubes and used an old brake cable from a motorcycle and cleaned out both tubes and the egr tube as well all were clear and free of any carbon buildup.there is a solenoid type of thing on the top of plenum/intake which allows egr gas to enter intake when it calls for such. Well that seems to work however under load it sounds like its rattling but i caint be sure because it only rattles under heavier load.

the rattle sound sounds the same as the old style heat riser rattle if anyone can remember what that anoying rattle is like.

Which solenoid thing are you talking about?
Job 2

Job 1

You guys are a big help will go out and check this out