Check engine light on - Code P0401 EGR flow insufficient detected


2

205 MPH

New member
Apr 21, 2008
1
I have a stock 2005 Ford GT that has a check engine light on. Scan tool indicates code P0401, Exhaust Gas Recirculation Flow Insufficient Detected. I've reset it but it came back on after about 60 miles.

Does anyone know the fix for this?
 
I notice on other forums they refer to a bad differential pressure feedback sensor or DPFB, I don't know if we have one but I think we have a MAP sensor on the passenger side of the engine under the SC snout, this I believe has to do with the EGR and may be a place to start.
 
see if you can find TSB05-3-1, it may help
 
Depending if you have to pass an OBDII emissions test, you can get a custom tune that disables the code and turns off EGR.

Somehow the ECU thinks that EGR gas in not flowing in sufficient quantity when commanded to do so. The pressure sensor is embedded inside the EGR valve assembly. If you have an SCT tuner you can download Livelink from SCT and look at the EGR parameters while running the engine to get better insight into the problem.
 
Got p0401 on the way to the TX Hill Country rally last week. Cleared it, came back again. Now i have p0401 and 0402, both EGR related codes. From what I can gather from cursory internet research, it can be caused by deposits in the valve or tubing, or the valve and/or sensor are bad and need to be replaced.

I haven't noticed any drivability issues. Any detriment to continue driving the car until I can get this addressed?
 
Any detriment to continue driving the car until I can get this addressed?
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No detriment, just benefit. A car with no EGR is much happier than car with EGR! No consequences of continued driving.
 
nota4re said:
No detriment, just benefit. A car with no EGR is much happier than car with EGR! No consequences of continued driving.
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Ha. Thanks Kendall. So, no issue with just turning it off with the tune?
 
None.... even desirable. Only issue would be bi-annual smog check which would fail.
 
nota4re said:
None.... even desirable. Only issue would be bi-annual smog check which would fail.
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Ah, but I'm no longer a Californian:)

But Houston still has a yearly OBDII scan along with a safety inspection. TXDPS allow one non-continuous monitor to be 'not ready', so if it's just the EGR, I should be ok. Thanks again, Kendall.
 
Check the orifices just past the throttle body into the EGR mess on the side of the supercharger to see if they are clogged. You should be able to see them with one of those little mirrors you can get at Harbor Freight :) after holding the TB open. Of course if they are, you have to figure out why.

PS Do you have an Accufab throttle body?
 
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Not exactly the same, but the EGR valve on my F350 fouls about every 20,000 miles. Easy to take off and clean the soot with solvent, allow to dry a minute or two, reinstall and good for another 20K.
 
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