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EGR mod CONS

3K views 57 replies 17 participants last post by  FULLTHROTTLE74 
#1 ·
I was wondering what kind of bad things happened with your trucks when you intalled you EGR restrictor plate...did you feel any lag or did you feel any gain...I am just wondering because I have done that mod and I'm trying to find out why my truck is not performing as well as i expect it to be especially with my mods
 
#2 ·
I've heard of some people having a serious knocking problem between 1900 - 2400 rpm. I think thats the range. But every truck is different, and yours may not experience any problems.
 
#3 · (Edited)
The EGR restrictor mod can and will increase nox emission and increase combustion temps. If the temps become too high it will retard the ignition costing you HP
BUT the EGR should be closed at idle and WOT so if WOT performance is suffering that's not likely the cause.

I think you problem is the IAT sensor and MAF mods.
Plus that TB spacer is doing nothing to help your HP either.

The screen in the MAF does not block any air flow. It's there to straiten the air flow over the MAF sensor so it can give more accurate readings. With out the screen turbulant air is flowing over the sensors.
 
#4 ·
yeah the lag was from the IAT and MAF....

did u do a plate or fitting? the fitting works better, altho hardly dangerous and i disagree on the merrits....
 
#6 ·
hardlydangerous said:
The EGR restrictor mod can and will increase nox emission and increase combustion temps.
Totally 100% beg to differ on that one!!! NOx formation is a direct result of higher combustion temps, for one. The 02's range for coding EGR low flow is well below where it needs to be in the first place. Adding extra EGR gas will not lower NOx formation, combustion temps of chamber temps, period, end of story. It only needs a small amount over 1%, some argue to as much as 10% total of the air fuel mix to reduce the combustion process temps which in turn lower the NOx formation to the lowest levels without hampering operation of the motor!! That is 100% complete fact!!! At just off idle our EGR system makes up for over 30% against the air fuel mix and then as the throttle opens lowers, but never is lower than 10% before EGR operation is shut down. It would have been wiser for GM to make a variable EGR valve so it was controlled equal with throttle opening, so I did this instead. If you get not SES light, it is well within the perimeters that the federal government established and we all know GM made sure it would always be within these ranges by a longshot!!

Newer 2 connector aluminum cased OBD's which are sometimes called the LS style comps have a much more aggressive timing curve than prior units. These units are much greater improved ones meant for max performance while maintaining emissions are are very touchy to mod against. Reflashing one at this point is futile since many areas are aggresively tuned allready and going further is taking some risk plus the fact areas are locked and unaccessible at this point in time. The people running newer styles can sometimes experience ping due to the fact its running a tad leaner due to restricting EGR gas, its not because of combustion temps at all, its trading EGR gas for burnable air on the same fuel trim, making it lean up some. Not every motor will experience this , nor will it throw a low EGR code. I had to open my EGR up over norm due to a light ping, still restricting the EGR flow but not as great.

Your problem as to running is the MAF ,smaller % the IAT. Older OBD2 would allow this MAF/IAT mod to take place cause its programming was not pushing limits. You play or replace your MAF and it will automatically unreport air flow and cause the motor to run very lean!! Couple that MAF reading with a reading to add timing due to colder intake temps, says it all. I've now got a 2001 4.3 and have learned this OBD2 LS style is very touchy to prior mods!!!!
 
#8 ·
964pt3 said:
Totally 100% beg to differ on that one!!! NOx formation is a direct result of higher combustion temps, for one. The 02's range for coding EGR low flow is well below where it needs to be in the first place. Adding extra EGR gas will not lower NOx formation, combustion temps of chamber temps, period, end of story. It only needs a small amount over 1%, some argue to as much as 10% total of the air fuel mix to reduce the combustion process temps which in turn lower the NOx formation to the lowest levels without hampering operation of the motor!! That is 100% complete fact!!! At just off idle our EGR system makes up for over 30% against the air fuel mix and then as the throttle opens lowers, but never is lower than 10% before EGR operation is shut down. It would have been wiser for GM to make a variable EGR valve so it was controlled equal with throttle opening, so I did this instead. If you get not SES light, it is well within the perimeters that the federal government established and we all know GM made sure it would always be within these ranges by a longshot!!

Newer 2 connector aluminum cased OBD's which are sometimes called the LS style comps have a much more aggressive timing curve than prior units. These units are much greater improved ones meant for max performance while maintaining emissions are are very touchy to mod against. Reflashing one at this point is futile since many areas are aggresively tuned allready and going further is taking some risk plus the fact areas are locked and unaccessible at this point in time. The people running newer styles can sometimes experience ping due to the fact its running a tad leaner due to restricting EGR gas, its not because of combustion temps at all, its trading EGR gas for burnable air on the same fuel trim, making it lean up some. Not every motor will experience this , nor will it throw a low EGR code. I had to open my EGR up over norm due to a light ping, still restricting the EGR flow but not as great.

Your problem as to running is the MAF ,smaller % the IAT. Older OBD2 would allow this MAF/IAT mod to take place cause its programming was not pushing limits. You play or replace your MAF and it will automatically unreport air flow and cause the motor to run very lean!! Couple that MAF reading with a reading to add timing due to colder intake temps, says it all. I've now got a 2001 4.3 and have learned this OBD2 LS style is very touchy to prior mods!!!!
:stupid: 100%
 
#9 ·
I did the mod on a 1995 cpi, drove it for 20 miles and the pinging and detonation causeed by the higher combustion temperatures was terrible.

Not worth it at all, most of people that do it and say that it makes a night and day difference are suffering from MENTAL horsepower.
 
#10 ·
BlazerLT said:
I did the mod on a 1995 cpi, drove it for 20 miles and the pinging and detonation causeed by the higher combustion temperatures was terrible.

Not worth it at all, most of people that do it and say that it makes a night and day difference are suffering from MENTAL horsepower.
Oh boy here we go again. The guy who has other problems that the EGR mod made him aware of so he's asking about running colder plugs cause the PING is back!! Cant you just get it that you have other problems??? How many times do you need to be told that??

I've got over 80% who say it has worked for them in one form or another.

18% not posting a word, cause they will not back 964pt3 cause he's pissed them off on other topics, quietly running the mod.

Other vehicle boards copying the idea to work with there own motors with about the same success rate.

2% that wont try it, think it causes this and that without ever trying not knowing the true useage of EGR, and some with other problems it merely helped come to light, but still say it WAS EGR modding that causes the problem but still to this date have the problem on and off again:dunno: :dunno: :dunno:
 
#11 ·
Thank god someone else finally called him out.This is the guy who likes to say BUD every time he thinks he knows what the hell he is talking about.I have watched you blame that mod for your pinging countless times.But you still post up for help for SEVER PINGING AND DETONATION!!Even after you took the mod off you lied on other forums saying your pinging problem was solved.You dont know how to fix your constant pinging problem but you are the all knowing when it comes to the egr mod.You dont know what your talking about.You dont know how to fix your own truck with even the simpelest problems.I like helping people and I dont mind helping you.But your continous ignorance of the operation and results of this mod are getting very played out.So you can come back and try to lie some more how this mod caused your damn truck to ping.When there are several posts we can go back and post up.That you are going nuts over not being able to stop your truck from pinging.I have forgoten more than you will ever know about auto repair BUD!!:ahole:
 
#12 ·
BlazerLT said:
I am getting the pinging problem coming back and I'm thinking on switching to a colder firing spark.

Which of the two are colder?
Hell this one you just recently posted.
BlazerLT said:
Yea, I'm getting that pinging to even on mild acceleration up hill.

Sounds like an old beater sometimes.

Wonder if I have a knock sensor gone or something?
I must have read this wrong.Because you said removing the egr mod solved that bad pinging problem that it didnt have until you did the mod.There are plenty more of these to.
 
#13 ·
BlazerLT said:
Oddly enough, I switched fuel brands and the pinging is gone.

Wow, never knew gas was that different from company to company.
Ok now he claims on another post that he fixed the problem by changing brands of gas.How convenient that was just after his :bs: was posted.
 
#14 ·
964pt3 said:
Oh boy here we go again. The guy who has other problems that the EGR mod made him aware of so he's asking about running colder plugs cause the PING is back!! Cant you just get it that you have other problems??? How many times do you need to be told that??

I've got over 80% who say it has worked for them in one form or another.

18% not posting a word, cause they will not back 964pt3 cause he's pissed them off on other topics, quietly running the mod.

Other vehicle boards copying the idea to work with there own motors with about the same success rate.

2% that wont try it, think it causes this and that without ever trying not knowing the true useage of EGR, and some with other problems it merely helped come to light, but still say it WAS EGR modding that causes the problem but still to this date have the problem on and off again:dunno: :dunno: :dunno:
I'll back you, I was very pleased with my EGR mod. It did cause my SES light to come on, but its an 01 and I expected that, and I'm too lazy to take it off and drill it out.
 
#15 ·
Yeah... His biggest prob is when you try to help him make something work, or he disagrees with you to any extent, instead of debating it rationally he throws a temper tantrum and starts treating everyone like shit... EGR mod caused his pinging... We try to help him and suggest that it could have brought to light an underlying problem and he goes ballistic instead of saying...hmmm...mebbe ill check that out...but no, his truck is perfect, LOL... Of course the EGR mod is gone, and his pinging is still there (or rather came back) and yet he still insisits the egr mod is crap to anyone who will listen instead of trying to understand the point of all these forums is to help one another...heh... Glad I'm not the only one that sees it...(But I'm sure he will attack me for this post)
 
#16 ·
I'm not pointing fingers, endorsing anything, or taking any sides, but I've got an EGR limiter on mine -- in conjunction with a supercharger -- and have yet to notice any pre-detonation/pinging. With an S/C, pre-detonation/pinging is much more prevalent, and I would think that if the EGR limiter promotes pinging, then I would be the first to experience it. So far, nothing, nada, zip, zilch. Not even an SES light. I've got one on my '98 and one on my wife's '01 Blazer -- neither has any problems.

So far, I haven't noticed anything in the way of drawbacks to the mod.

Fine, maybe the EGR limiter made the pinging more prominent in a truck or two, but just reducing the EGR gasses will not cause the detonation itself -- that is caused by something else entirely.
 
#17 ·
Im sure he is mad as hell.He just needs to listen alot more than he does shooting off at the mouth.I will still help him with any problem he has with his truck.Because thats why he comes here just like everybody else.
 
#19 ·
""In short, it doesn't look like the EGR limiter (or the other mods) is likely to cause an emissions failure in a healthy engine.

Granted it has been two years and 21k miles, but here are the results of the emissions test I had last week.
Reading Old /New
HC CPM 0.0591 /0.1430
CO GPM 0.8043 /2.2456
CO2 GPM 440.1836 /494.5390
NOx GPM 0.2991 /0.2133""

I find it funny that a few seem to say this and that, but here are the results of and emissions test done by a user. Notice that with running the EGR limiter his NOx output was actually lower. Kinda throws a bone into the increased combustion temp and cylinder ideals some have!!!
 
#21 ·
actually restricting it (not eliminating the EGR) will increase gas miledge, and it's not meant for WOT or higher RPM's, it's more for base throttle response and lower end torque.... I can personally say my car had lower nox/hc with it on then off, my gas miledge improved by about 2 miles per gallon...I've been running this mod for over a year and it's been benficial.. Nobody says you have to use it, but you don't need to put down those who do and who are happy with it....
 
#22 ·
hmmm thats odd... I have seen a 2 mpg increase with my restrictor on. So has alot of people
 
#26 · (Edited)
Thanks for the personal unwarrented attacks. Did I mention anyones name? Did I say anyone was wrong?:confused:

Wow guys, I'm not mad, but whos the one ranting and roaring?:rant:

Oh yea, and the pinging problem was due to poor fuel as was referenced by a guy that had the same problem with petro canada fuel in his 4.3L. No more pinging since I switched to Esso fuel. This comment below was made without him knowing what brand of fuel I was using.

hardlydangerous said:
I agree
I used to get bad spark knock and valve train nosise in my car when I filled up with Petro Can fuel, Now that I run Sunoco or Esso I have had no problems even under much harder loads.

Different fuel companies and different additives can make a big difference.

Some guys in the turbo world are so picky about fuel brands it's not even funny.
Love you all, have a splendid day. :phil:
 
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