In researching this amazing topic, I find there are various version of ECUs produced; seemingly only one hardware version; along with varying software versions. What is interesting is that at least ONE (probably more) of these versions allow the simple EGR resistor trick to work, without any other fancy modifications (the famous youtube video resistor trick). As owners for 2004-2006 ECU versions have reported success using the simple resistor trick. On Ebay you will find various versions of ECUs for sale, but you do not know the magic one(s) that allow the simple resistor trick to work! By the way, my EGR measures 1846 ohms, measured with a Craftsman multimeter (not a lowly Harbor Freight multimeter). Now to go find a resistor close to 1846 ohms and try the test! Also, if you get the T21recall, it will change your ECU file part number to 647 900 00 00, and the resistor trick will definitely not work!
EGR delete kit
- Thread starter Badmonky
- Start date
Lance Sargent
New member
Hello, Do you unplug the wire from the air filter box & leave the wires attached to the MAF sensor?
Nautamaran
2004 140” HRC 2500 (Crewed)
With the MAF unplugged the ECM will record a fault code and then use default airflow values for fueling calculations. Without the live MAF value the ECM has no feedback on the EGR commanded, so will simply assume that it is working. The result is a very lean fuel/air mixture and increased combustion temperatures, so your exhaust will take on the brown hue of NOx emissions, especially during lower power cruising when there will be a great excess of oxygen in the charge air.
-dave
Lance Sargent
New member
Thanks Dave
TGEMilwaukee
Member
Try not to overthink things..
An external EGR Valve will work for testing an installed failing EGR valve. Both short and long term....
An external EGR Valve will work for testing an installed failing EGR valve. Both short and long term....
flman
Well-known member
FIFYHas this gone way off topic?
Is this what I think it is?
flman
Well-known member
No more EGR problems, or soot and oil vapors plugging up the intake, and no CEL. Win Win!
Nautamaran
2004 140” HRC 2500 (Crewed)
This is the ECM watching for MAF feedback, and seeing that the EGR valve isn’t having any effect on air intake volume. Your EGR isn’t moving as commanded by the ECM, and may be sticking open (or you may have poked a resistor into the harness?)
Disconnecting the MAF will remove the feedback data and prevent p0401, but then you’ll have a “MAF circuit open” error.
This is hogwash. No gasping takes place... it’s more akin to breathing into a paper bag when you’re hyperventilating.
A properly functioning EGR acts like a throttle body in a spark-ignition engine, limiting the incoming air during lower power operation when the air isn’t required and the engine would otherwise be running ridiculously lean and belching NOx. Of course if your EGR is malfunctioning and sticking open then you do run short of air - you don’t run a marathon with a paper bag over your mouth! - and if there’s also no MAF or O2 sensor data available you’ll likely make a bunch of soot since the ECM assumes stock volumetric efficiency.
There is nothing fundamentally wrong with having a properly functioning EGR system on a diesel, though I understand the frustration of maintaining the one on the 612 and I too would be looking for solutions… but that solution is to convert to the 647’s intake and EGR valve, not to circumvent the whole system.
-dave
Before I replaced the EGR valve, I drove around for years with the resistor in place (the EGR valve shut vie EGR spring tension) and my finger on the OBD reset button. Depending on throttle position and other factors, sooner or later the P0401 pending code will come up and loose the use of full engine power. A quick code clearing will reset the limp mode to allow enough/full throttle as needed to keep up with traffic.
I take it there is no easy mod to bypass the MAF/O2/EGR feedback loop in the 2006?
Nautamaran
2004 140” HRC 2500 (Crewed)
That requires “tampering” with the ECM firmware and is essentially what the EPA charged GDE for doing.
Cheyenne
UK 2004 T1N 313CDi
A 906 is an NCV3 so you are asking in the wrong area of the forum. Try searching the NCV3 sections.
Nautamaran
2004 140” HRC 2500 (Crewed)
Scroll back and read the rest of this thread…
If your MAF sensor is functioning properly, the ECM expects to see a drop in MAF when it opens the EGR valve. No MAF drop = No EGR flow = code p0401 “Insufficient EGR Flow” pending/stored and the MIL/CEL on.
-dave