Let me try and clear up some of the misconceptions in this forum -
There are TWO distinct components to the EGR system, even though they are listed as the same thing in the mentally-retarded service manual. The FCV or Flow Control Valve (or EGR Control Valve I've heard it called as well somewhere) is the big butterfly valve with the electric motor attached that lives ON THE INTAKE ELBOW right where the intercooler hose connects on the driver's side.
The EGR valve ALSO has a valve of some sort, but it is a much smaller (and not removable) component. The EGR is bolted to the engine block itself, under and behind where the FCV is.
The FCV can be electrically unplugged without a CEL happening... IF you have either an SEGR or a GDE tune. It is NOT NEEDED FOR ANYTHING ELSE by the computer, and pulling the butterfly valve CANNOT HURT ANYTHING AT ALL. Leave the electrics connected if you want (I left mine hooked up) and forget it is in there.
OK... SEGR versus GDE. At the risk of calling in the black helicopters and mind control rays... Warp is correct. The SEGR device completely disconnects (electrically) the EGR and leaves it in whatever state of closed it happens to be in. This is a good thing. GDE's tune DOES NOT USE THE EGR AS ANY KIND OF "blow off valve" like their literature states. I have physically monitored the functioning of that part of the electronics, and the command to open the EGR is given EVERY SINGLE TIME you take your foot off the gas pedal. The circuit path goes from an "off" state to an "on" state for just about half-a-second each time. This is not in dispute, they claim exactly what they are doing: Reducing the amount of EGR used while not "eliminating" it entirely.
Here's the part you have to decide for yourself about this: The EGR itself is an electric motor operating a screw, to open or close off the port. This motor takes an amount of time while the signal is either on or off, to change state. When the signal changes state, so does the motor... Again taking an amount of time to physically MOVE from A to B. Can this motor do this in the half-second allotted? I personally do not think so. Further, rapidly reversing polarity on an electric motor is a FAST way to annoy it and cause it to fail out. This isn't a big issue for our purposes, we don't like that thing anyway, and it usually only lasts about 16k miles in stock form anyway! HOWEVER... Do you want to risk that the thing fails in the OPEN position, leaking all your boost out? I sure don't!
GDE is in a tough position with the government here, and we need to protect them. In the case of most aftermarket products, there is at least a statement of "for off road use only" from the manufacturer, and the liability is passed to the consumer entirely. With an engine tune, it is MUCH harder to justify that, because in most cases (especially ours!) the vehicle simply is a giant ornament without that computer. You can't remove the computer (with that tune) and drive home on the surface streets. So you WILL BE USING THE TUNE ON THE HIGHWAYS... Which means that GDE cannot LEGALLY remove the function of the emissions control systems. Calling it's function by a different name is marketing. If it walks like a duck, quacks like a duck, but craps soot... It is still a working EGR valve.
The SEGR device does what GDE cannot, because it wasn't developed by any corporation that can be sued into silence. It was developed and then released as an open-source set of plans... That when installed, the EGR valve can be left plugged in because the physical power wire is cut elsewhere. The EGR cannot open, but the computer "THINKS" it has opened, because of the genius of the design. As such, no CEL, and the computer is happy.
Now... Physically blocking the EGR off from the intake and / or the exhaust manifold. It is a strange thing, but it seems my own EGR tubing has mysteriously "rotted off" at the connecting ends of the intake and exhaust. Oops? The ends of the tubing are a strange flange, but they can be cut off and retained, and you can (if you are handy with a welder) fill the tube with welding wire to seal it off. I followed that up by filling the inside of the tube with high-temperature silicone to completely seal the blockage, then just clamped the flanges back into place. The EGR device itself is still bolted to the engine block... Someday that might "fall out" too, you never know. But as you can't physically SEE it unless you know exactly where to look... The loss of that tubing seems to be a minor thing to me. Your opinions may vary.
Viva la revolucion!
_________________ Proud supporting vendor of LOST Jeeps TRAVELING CRD TECH. I come to you! Need help? Just ask! I've taken it apart more than most. Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN Over 225 CRDs currently driving with my valves, timing belt, rockers, or ARP Studs. Bad noises = REALLY bad things.
|