OK, anybody got specific instructions on disconnecting the EGR properly?
Will it throw a code?
EGR problems will affect fuel mileage. Will disconnecting the EGR improve mileage?

 

Good question. There was a guy on the diesel stop that said he disconnected his EGR and his MPG improved. Obviously it's there for a reason though and might not be good to have it disconnected.

 

I have read there is no change......????.wonder why

 

In my discussions with the diesel tech at the service dept I use, he said the EGR valve can impact mileage. He went on to say that the EGR valve could malfunction and not throw a code.

I also believe that tampering with emissions devices is borrowing trouble.

 

I drove with mine disconnected for about 1200 miles and found no effect to gas mileage and other than no difference. Initially I though it ran better but I think that was all in my head because I hooked it back up and felt no difference. In fact Mr. Lamkin drove my truck with I connected and said that it ran great. I value his opinion very much and from what I have read that the only advantage to disconnecting it is that it keeps your Intake tube clean of oil. That is the only advantage I can see so far and the intake issue I have not looked at myself, I just read it here.

 

I unplugged mine a while back, probably 3000 miles. In terms of top end power, it will make no noticeable difference, but your turbo WILL spool marginally quicker. The EGR extracts exhaust air pre-turbo in these motors; by this token, any air the EGR uses is subtracted from the quantity that could be powering the turbo, but instead is rerouted through the intake. By pulling the plug on top of the valve, the valve is locked into the closed position and will prevent any air from being extracted. This is valuable air that, at idle-2200 rpms (estimate) will assist in getting your turbo boost up. I would be very interested to see the torque curve on a dyno with the EGR enabled vs. disabled. As for answering your original questions:

Simply pull the plug off the top of the EGR valve and wrap both male and female ends in tape (or at least thats what i did)

Yes, it will throw a code if you read it with NGS, but can simply be cleared with a tuner (diablo, superchips) or just unplugging the battery. The check engine light DOES NOT come on.

As for gas mileage, i do not carefully calculate mine, but it SEEMS to have boosted mine marginally, maybe half mile to the gallon.

PS- i also removed the throttle plate from the intake elbow (used for backpressure for the EGR, the plates are only in early model 03's and the new 04's) Both of these WILL decrease the time it takes for your turbo to spool up, by a noticeable yet not drastic amount.

 

Off and on for several 1000s of miles, I can see no difference in performance with or without the EGR, but it sure is simple to connect/disconnect. Never has thrown a code or SES light. But, what the heck, its a mod, right?

 

The main purpose of the EGR is to direct exhaust gasses, (oxygen depleted air) into the intake manifold. This supposedly reduces combustion temperatures and oxygen content that is necessary for the formation of NOx emissions, there by reducing NOx emissions. Some of the exhaust gasses from the cylinders is diverted through the EGR before reaching the turbocharger and routed back into the intake manifold. This means that the gasses going through the EGR have to overcome the pressure in the intake manifold to enter it. It is not unreasonable to assume that at high loads, the boost from the turbocharger in the intake manifold becomes high enough to prevent exhaust gasses from the EGR from entering the intake. In other words, under heavy load the EGR may not be doing much. If that is the case you wouldn't notice much difference at full throttle with the EGR disconnected. That is probably why people don't seem to notice increased power. It may be worth mentioning that this may be the main reason that many say the 6.0L PSD needs some exhaust backpressure to run correctly. Without sufficient back pressure in the exhaust the EGR will not be able to force as much exhaust gas into the intake. I think this has the potential to have a significant impact on low and mid load performance.

Regards,

Morris

 

You analogy is excellent, makes perfect sense.

 

is the EGR valve located on the Intercooler to Manifold down-spout or 90* neck? If not where is it?!?!?

 

how difficult was it to remove the throttle plate?

 

The EGR is located on a small black cylinder (the black cylinder is the valve itself) right between the oil filter housing and intake elbow on top of the motor-just pull the plug

As for the throttle plate, it is a piece of cake. Here it goes, step by step- take the clamp off the plastic hose connecting the intercooler to the aluminum intake elbow. there are four bolts holding the elbow onto the plate below it. Remove the bolts and pull the intake elbow off. this will reveal the plate, mounted to a crossbar going across the intake assembly where the motor for the throttle plate and its position sensor are located. There are two small screws holding the throttle plate on, #10 torx if im not mistaken (youll have to check, i cant remember) simply rotate the plate to the closed position and remove the two screws. It would be in your best interest to have a magnet handy to pick them up, you DO NOT want to drop them down the intake. pull the screws out and rotate the throttle plate back to the open position, remove it, and bolt the intake back on. Clamp the hose back on, and your done. If a 17 year old can do it, you can...its not hard, and its well worth the 10 minutes, just IMO...

 

Good to see I will be able to do it, me being 18 LOL

 

What I would have given at 17 or 18 to drive a BRAND NEW diesel pickup, let alone any new car or truck.

 

one thing i forgot to mention- the difference will only really be felt at partial throttle. the modification DOES make a small difference at WOT, but only in first gear, and not to the extent it does below 3/4. I have not thought of a logical explanation for this, it is probably due to the things mobandy listed in his excellent technical explanation.