Keep getting this code on my 2000 2.5l, I've put two new egr pressure sensors on it along with a new connector(dongle/plug). Both sensors lasted about 100miles each before the CEL came on each time. Anyone have any suggestions to get this fixed permanently? Wasn't sure if you can somehow clean the egr? Just strange to me how the new sensor(s) kept the CEL off for 100miles before it came on again unless something reset and that is the approx. threshold.

 

Welcome to the forum

P0401 Exhaust Gas Recirculation Flow Insufficient Detected

So this is not specifically a sensor code, there are EGR(DPFE) sensor codes like these
P0403 Exhaust Gas Recirculation Circuit Malfunction
P0404 Exhaust Gas Recirculation Circuit Range/Performance
P0405 Exhaust Gas Recirculation Sensor A Circuit Low
P0406 Exhaust Gas Recirculation Sensor A Circuit High
P0407 Exhaust Gas Recirculation Sensor B Circuit Low
P0408 Exhaust Gas Recirculation Sensor B Circuit High

P0401 "could be" a problem with the EGR sensor just less likely if its the ONLY code
This is why you should never "Google" just the one code number
Look up the code on a FULL LIST so you can see the codes the computer did NOT choose, that will help with diagnoses
You can see a older Ford full list here: https://www.therangerstation.com/tec...II_codes.shtml

DPFE sensor has two hoses that run to EGR's pipe, one is closer to the EGR valve than the other, so when computer opens the EGR valve the pressure in the closer hose should drop more than the farther away hose, simple system
P0401 means the difference wasn't enough

The computer can only test this system after engine is fully warmed up, so after at least a 15min drive, so miles don't matter, its drive time over 15min, and computer runs several tests on other systems after full warm up, so having code reset after 100 or even 200 miles is not unusual, if you did short trips, not one 100mile trip

I would pull off 1 hose on DPFE sensor and blow thru it, make sure its clear, then do the same on the other hose
Then pull off the other end of the hose and plug it with finger and blow again, make sure hose holds pressure, no cracks or breaks
Do Not mix up the hoses, they have an order on the pipe and the sensor

Next get a length of vacuum hose that fits the EGR Valve's vacuum port
Put it on the EGR valve
Start the engine
Suck on the end of the vacuum hose to open EGR Valve all the way, engine should stumble and even stall, if not then EGR valve and/or pipe is clogged up and will need to be cleaned

Next, follow the EGRs vacuum hose back to the EGR solenoid(modulator) unhook that vacuum hose and check it for cracks/breaks, i.e. blow into it with finger on the other end, it should hold pressure

If everything above tests as OK, then you would replace the DPFE sensor to see if its the problem

Just a heads up on DPFE sensors
ALL exhaust has water in it, that's why water drips from tail pipes and exhaust systems rust from the inside out
Gasoline(a "H"ydrocarbon), burned using "O"xygen gives a by-product of H2O(water)

The DPFE sensor hoses have exhaust inside them so "water vapor" is inside them and the sensors chambers, every time engine is turned off and cools down the water vapor condenses on cooler parts, like inside the sensor and rubber hoses since they cool off faster than metal exhaust parts
This is why DPFE sensors often fail, chambers get damaged by the water vapor
The hoses should also run "downhill" from sensor to pipe as much as possible, to allow any condensed water to run down and out to exhaust system, dips in the hoses should be avoided as water can collect there and block "true" pressure readings, which is why first test is to BLOW thru these hoses to clear out any water

 

RonD,

Wow... just wow!

I can't say enough. Too possess knowledge is one thing. Being able to disseminate it verbally is another. Being able to disseminate the ideas and diagnosis repair steps by way of the written word in a clear concise understandable fashion is a feat rarely accomplished. You sir are the BOMB!!!

I did a search on the P0401 code and this came up so... I don't have to ask any stupid questions. I can get right to work.

Thanks, Rickisan