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EGR delete?

42K views 39 replies 13 participants last post by  brent_m 
#1 ·
Does the EGR valve do any good? Do they make a delete for it?

Just wondering if it is worth the 70 dollar part to replace or not. I'm getting code P0406.
 
#3 ·
What engine do you have? And no, they are never good.
Total and complete BS. The EGR System is one of the few emission control devices that actually, for the most part, does some good and not cause a big hit to performance and economy. Deleting it, aside from causing you to fail the emissions test, may help shorten the life of your engine due to unnecessary increased combustion temperatures over the life of the engine, cause MIL/DTC codes, and won't do much to improve engine performance....if anything it may reduce performance (timing) by retarding the timing due to the increased combustion temperatures and possibility of the PCM forcing knock retard. The biggest down sides of the EGR is the potential of increased carbon buildup and it's response to throttle position changes lags.....is not instantaneous.

Here's a portion of a write-up dealing with the EGR System:

"The substitution of burnt gas (which takes no further part in combustion) for oxygen rich air reduces the proportion of the cylinder contents available for combustion. This causes a correspondingly lower heat release and peak cylinder temperature, and reduces the formation of NOx. The presence of an inert gas in the cylinder further limits the peak temperature (more than throttling alone in a spark ignition engine).

The gas to be recirculated may also be passed through an EGR cooler, which is usually of the air/water type. This reduces the temperature of the gas, which reduces the cylinder charge temperature when EGR is employed. This has two benefits- the reduction of charge temperature results in lower peak temperature, and the greater density of cooled EGR gas allows a higher proportion of EGR to be used."
 
#5 ·
Some say EGR delete helps with performance and economy. I am not buying it, but in the interest of "unofficial research" I just went out and shut the EGR System off in my Hemi LX (modded exactly like my Hemi WK) using a Diablosport Predator Tuner....circa about 2006-2007, which is before they eliminated this feature. Seems the EPA got after them because it was disabling part of the emissions system. I was also going to do it on the WK but by 2009, when I bought my WK, they had already removed the feature. With my onboard DashHawk I can monitor almost everything in real time, so I'll look at things like engine operating temperature (normally runs 190-200*), knock retard (normally 0 unless on it hard, then momentary ~2-5* retard), timing (which is usually all over the place so may not help), and verify that the EGR System is indeed turned off. I'll also do fuel economy calculations (manually using GPS mileage), as the LX is pretty consistent in fuel economy....14-16 mpg in town (depending on amount of stop and go) and 26-28 mpg on the highway at ~63-67 mph. I'll report back in a week or two after I do a few short (~75-150 mile) trips (one of the benefits of retirement) and a little around town driving. Should be interesting, because inquiring minds want to know, and besides I like to experiment/tinker.
 
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#7 ·
Ah....... someone is finally going to answer the question. I'm surprised someone still has the R12 tune on the predator. It's rare to see someone who had the brains not to update. I wasn't so smart and had to get a tune to turn it off to install the delete kit.
 
#9 ·
I have all the Predator "crom" files for both the LX and WK on the computer, but I don't think you can install earlier ones back on once you've gone to a newer version.

By the way, my son and I installed the 3.06 Limited Slip Getrag in Maggie last weekend. Took 5 hours with no problems......just a small PITA. Hope this minor change in gearing won't upset the "unofficial testing" of the EGR delete. We'll see how it goes.
 
#8 ·
Jeff, if you're getting the code, reset it and see if it almost immediately returns. Symptoms of a bad EGR Valve are, low speed (~35-45 mph) surging, rough almost stalling idle, and poor performance and fuel economy. Many have experienced failures at relatively low mileages, while others have lasted over 100K. The one on my WK failed around 60K. The very best way to check the valve is with a computerized diagnostic tool with the capability of manually operating the valve, or with an actual EGR Valve tester. I have both, an Autel DS708 and an AC Delco Model 47062 EGR System Tester and Model 47001 Domestic/Asian Adapter Kit. This way you can see if the valve is operating as commanded by the tester(s). Also, I believe all of the valves you can get today are made in China and some have experienced bad valves right out of the box. Try to get a "name brand" like Wells or Standard Motor Products, not some no name one. Do a search and see if you can find one of the "How To's" on the forum. It's not a tough job, but one bolt can give you a problem. Also, be careful with the tube seal where it goes into the intake manifold. If you ruin it, you'll have to go to the stealer to get another one, as I don't believe you can get one at your local parts store. When I did mine, I didn't even remove the tube from the manifold.....just rotated it out of the way and tied it off while I worked on the valve. Once you get the "difficult" bolt out (IIRC, it's the inboard one) cut about 3/16 in. off the threaded area and grind the recess of the head of the bolt. This will make it easier next time.....if there is a next time. Good luck and let us know how it goes.
 
#11 ·
Just went out and checked the data on mine:
--U7135
--Built 08/27/08
--Crom Ver. R09 08

Looks like I didn't update mine at all.

Just a little prelim and first impressions on the EGR delete after about 100 miles of mixed city/rural driving. I'll do a short 150 mile trip tomorrow to further see if there are any differences:
--It's definitely shut off......all zeroes on DashHawk Commanded %age EGR and Error %age EGR
--No difference in engine operating temperature
--No noticeable difference in fuel flow and fuel trims
--No difference, so far, in fuel economy (currently reading 16.5 mpg), using only EVIC at this time. Will do hand calculations and fill up before and after for tomorrow's little trip.
--No significant difference in Knock Retard (KR) at Wide Open Throttle. I saw 5* KR (seemed to stay at that a little longer than normal) from ~50-90 mph on one WOT run.
 
#12 ·
I did a little road trip today in my Hemi LX (modded exactly like my Hemi WK except for cam advance) with the EGR shut off to see if there is any difference. My normals for this vehicle are found in Post No. 5 of this thread. Here are the results:
--156.4 miles on 5.5 gallons of non-ethanol fuel. Tank was filled with 3/4 full of 87 and 1/4 full of 91 fuel before departing and, using the same pump on return it was refilled with 91 octane non-ethanol fuel. This calculates to 28.436 mpg for the trip. This is about normal for this vehicle.
--Altitudes ranged from ~2400-4000 ft.
--Temperatures ranged from ~72-84*F. Air conditioning off outbound and on inbound.
--EVIC reading for the outbound leg was 26.7 mpg and the inbound leg was 30.7 mpg, so the EVIC was not that far off when these numbers are averaged (28.7 mpg). This is about normal for this vehicle.
--Vehicle speed both inbound and outbound was 65 mph except for 3 WOT runs, one to ~90 mph, one to ~101 mph and one to ~97 mph.
--MDS (both ways) was active ~85-95% of the time. This is normal with this vehicle which has aftermarket cam advanced 6* for a total of 10*.
--EGR System was shut off with the Diablosport Predator Tuner the entire time. Tune is a modified 93 octane tune.
--Operating engine temperature was 189-192 for the entire trip. Thermostat is a 190* with fans coming on at 200*. This is normal.
--Fuel trims and fuel flows were normal.....long and short term 0-minus 5, fuel flows, ~2.1-3.5 gph, depending on road incline/decline.
-- Knock retard ranged from zero at cruise to ~6-7* momentary at WOT. This is slightly higher and lasted slightly longer than normal.

So, my assessment of the "EGR DELETE" after about 250 miles of driving is that in most ways it makes no difference whether it's on or off. The only thing that was slightly different was the amount and length of time Knock Retard occurred at WOT. Everything else was as it is with the EGR working. After the fill up today I'll run this tank down and then turn it back on so I don't encounter any of the issues I identified in my Post No. 3.
 
#21 ·
--EVIC reading for the outbound leg was 26.7 mpg and the inbound leg was 30.7 mpg, so the EVIC was not that far off when these numbers are averaged (28.7 mpg). This is about normal for this vehicle.
Are you saying you get near 30mpg?! What engine do you have? I barely got 18mpg on my V8 prior to my lift and larger tires and now I barely get 16 if I am lucky!
 
#13 ·
I wonder how the EGR would compare on a diesel. I deleted mine on my CRD, and after seeing some of the piping for it I can say for my OM642 the EGR system blocks a lot of the intake air coming in through the "throttle body". Also, since the OM642 is turbo'd you get some oil blow by that does make its way into the intake track and mixes with the sooty diesel exhaust from the EGR and does clog the entire intake track up quite a bit.
On a gasser, I don't see any advantages other than if you were actually building a race/high performance engine and wanted a cleaner look in the engine bay. I deleted my EGR on my 85 corvette because the valve was bad and for $50 I could buy block off plates or for $250 I could buy a new EGR valve, which still wouldn't guarantee that it would work correctly due to the age of all the pieces involved.
 
#16 ·
I am not a diesel guy, but if I had one that was restricting intake air flow and contaminating the intake tract, I'd for sure pull it all off and do some testing. When you deleted your EGR, do you get a light, or do you have to also change the computer setting like I did for my testing? The older 5.7 gas tuners had a feature that would just allow you to turn it off without removing/blocking anything. I don't know if that would be picked up on emissions tests either. Would be curious though.
 
#15 ·
Yes, I am sure that would be very true, but you shouldn't be getting much anyway if you have a catch can on it. Both mine, with catch cans, have very little accumulation, just stuff that easily wipes off. Catch cans to catch a lot of crap though.
 
#18 ·
That is not true!
Deleting the EGR improves power, lowers, engine temps, saves motor, all you get is a code that you can easily fix by putting new valve in if you have To do an emissions test.

I have deleted every diesel I own and everyone of them have had Zero problems related to motor!!
 
#20 ·
I have driven 600kish hard miles towing off roading in the desert, and I have had zero problems with deleting emissions.

Now saying that don’t take advice from anyone about a diesel situation when their primary vehicle is a gas or they say I just replaced it I didn’t want any problems!!
Diesel motors used to run over 1.5 million miles before needing over haul ( engine rebuild ) now every truck in our fleet only run 300,000-380,000 miles before they detonate due to Carbon build up from improper fuel burn and Carbon being reinserted into combustion chamber, rings wearing early causing gauges or scaring of cylinder walls, over heating due to cylinder walls being sand blast until eventually it blows a hole through cylinder into next cylinder! I’ve seen intake valves blasted till it was also warn to failure!

The 94.5 Cummins motor had a turbo, intercooler, mechanical pump, air cleaner, and a muffler. I know of one still running at 1.2 mil. Miles. Still running strong, cylinders hold good compression, uses 1 quart of oil every oil change.
 
#24 ·
Did I miss something? 23 posts and noone noticed this debate is mute for registered vehicles.
It is illegal to remove or render inopertive. Thats a federal law.
 
#25 ·
Maybe some of the diesel folks are above the law?
 
#26 ·
There are plenty of dumb/misinformed/outdated laws out there. Lack of education and understanding leads to many laws that don't make any sense.

If you want to delete, delete. If you don't want to delete, don't delete.

There's plenty of laws regarding sex positions and other things you can't do in that regard. Plenty of people "disobey"
 
#29 ·
Does the EGR valve do any good? Do they make a delete for it?

Just wondering if it is worth the 70 dollar part to replace or not. I'm getting code P0406.
As info....I recently replaced valve cover gaskets on my 08 Sport. While I had everything apart I Should have replaced EGR. Difficult to remove based on location and "star" headed bolts. I did attempt to clean in place with some MAF cleaner.

I typically get 21 mpg (OEM Computer) on highway at 68mph, keeping rpms just below 2000. Most recent roundtrip Florida to Ohio avg 18.5 all the while EGR throwing 0456, 0406, 0403. My 'round town mpg avg typically holds 13.9. I'm at 12.1 mpg with EGR throwing codes.

......so yes I'd say the cost of part is justified based on lost mpg alone.
 
#30 ·
Welcome to the forum. Yes, if the EGR Valve is erratic in its operation or, if it's stuck open (usually from carbon), it'll really mess with the fuel trims and timing. If it stays completely closed at all times, it doesn't make much of a difference. When mine went bad (about 60K), it was very erratic and would indicate rapidly changing commanded valve settings, some being unrealistic, and the correction would try to actually correct the settings, but was always way behind and could never catch up. My symptoms were as stated before, low speed surging, rough, erratic idle and lousy fuel economy.
 
#32 ·
Welcome to the forum. What year is your Hemi and how many miles on it? Is that melted intake manifold plastic? If so, I would suspect an EGR Valve that is not closing completely and is continually pumping hot exhaust gases into the manifold. I've never seen this before. If this is the case, you most certainly should have some DTC's showing AND some noticeable issues with idle and fuel economy at a minimum. What does the back side of the throttle body butterfly look like...covered with caked on oil or ??? Any other issues with the way it starts and runs? Any mods to the engine?
 
#33 ·
Hello! my old gch wk hemi 5.7 has 70,000 miles on it. But while cleaning the throttle body I ran into this problem. The only random fault that gives the dtc is p0406. I have cut the pipe that enters the admission, I have changed the valve but I am seriously thinking of canceling it with a piece of aluminum. And naturally it is possible that it shows p0401, p0403 and p0406 (low gas flow, current and sensor) with which I will have to complete the electronic cancellation of the valve, with the scanner.
 
#36 ·
So, that is melted plastic then? Looks like the valve is stuck open...probably carbon. How much did you cut off the EGR tube? The only real good (and complete) way to eliminate the EGR Valve is by blocking it off with a block off plate AND shutting off all of the related EGR DTC's. The only way I know of doing that is with an HP Tuner. Be aware, if you're in the States, it is illegal. I am guessing that you're somewhere in Europe though.....Scandinavia or Germany maybe?
 
#37 ·
I am surprised you didn't have more symptoms. The way you cut your EGR tube off is about the same way I have them on both of my Hemi's. I still run the EGR system on both of them too. This emissions control device is about the only one that actually does "some" good (reduces combustion temperatures) and is normally fairly trouble free. I've changed only one EGR Valve on mine in over 17 years. On both, I also have catch cans, use Redline Oil products, and top tier non ethanol fuels.
 
#38 ·
Hello! First of all I want to say you that I am from Buenos Aires, Argentina and my family is from Patagonia, ( a beautifull place named Bahía Manzano) where the hemi must come and go on trips of 2,500 miles aprox, three or four times a year. I had other hemi engines, but I never see this situation before. I try to assume that the valve was open and the pipe "acted as a torch" on the plastic. The EGR system makes me think that can be something like "breathing our flatulence or exhaust gases" (poor car:ROFLMAO::ROFLMAO::ROFLMAO::ROFLMAO:).
I know that it is a highly discussed topic. We may have different opinions. Personally I don't like re-enter inert gas at the intake, (but I understand the nox2 issue) . I clean and maintain the engines carefully, observing each piece in each revision. (In my opinion those reviews made me discover this issue. )
The check engine accused as a code but randomly (it could mark the fault one day and weeks not turn on) the p0406. Only when removing the throttle body did I notice the problem. The valve change hadn't solved it. That's why I cut the pipe and now I plan to cover the egr. Dear friend sorry for my english... (perhaps you read semantic problems :D)

Tire Automotive side marker light Wheel Car Land vehicle

Automotive parking light Automotive side marker light Wheel Car Tire
 
#39 ·
Sorry I was so far off on your location. I've heard Argentina has a lot of pretty places. Anyway, glad you're not in Europe the way things are over there. Also, there is not a thing wrong with your English......in fact, it's better than some others that post on these forums.

By the way, your Jeep really looks nice. You're right, if that valve stays open, it is just like a torch blowing into the intake. Shortening the tube should help eliminate that. Did you inspect the valve you removed? Since the problem remains the same, there may be problems with other components, especially the wiring to and from the PCM, or even the PCM itself. The PCM, using sensor inputs, controls when and how much to open the valve. Do you have access to an advanced computerized diagnostic scanner....one that can check the operation of the EGR Valve and also read live and freeze frame data? This can help you isolate where the problem(s) may be.

Good luck with this and please keep us posted on your findings and repairs.
 
#40 ·
When I was tinkering in AlfaOBD, there's an option to open that EGR valve, which makes the engine run really rough at idle.

So if it's stuck open, wouldn't it run really poorly at idle?

Also, is it possible an aftermarket tuner is to blame?
 
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