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taking off egr, is it harmful

1K views 39 replies 13 participants last post by  stevenr816 
#1 ·
hey im taking off all of my emissions stuff and need to know if taking off the egr valve is harmful?

does the egr valve low the exhuast temp enoughto really matter?
would a egt/pyro meter tell me the temp differences?
steven
 
#3 ·
you will destroy your motor if you do that. dont do it..........
 
#6 ·
some people will tell you to keep it...some people will tell you get rid of it that it doesnt matter.
All the JDM engines dont have it. We have it for emmisions control.
Now if you have to get smoged or get your car inspected then i suggest you keep it.
I took it off on my old motor it didnt do any harm.
Get block off plates from somewhere (online store) i dont know where.
 
#8 ·
my first post wasnt directed to your post :lol: it was for the EGR post. ;)
 
#9 ·
its purpose is to cool the egt down so you don't produce NOx or whatever it is.

now...it isn't functioning at idle nor does it function at WOT

so if you are building a track day car and weight is an issue remove it..otherwise there is no point in removing it...actually it will do more harm than good.

other words don't remove it unless you have too.
 
#10 ·
He's on the right track.

The only thing he's missing is that he isn't telling you why you'll run pig rich if you remove it. What your EGR (Exhaust Gas Recirculation) does is put exhaust gas back into the flow of air going into the combustion chamber. However, exhaust gas contains no oxygen which means it will not burn. So, when the PCM tells the EGR valve to open, it's effectively reducing the volume of your cylinder by restricting the amount of combustible air/fuel mixture entering the combustion chamber.

Less fuel/air = smaller explosion = lower exhaust temp and lower NOx for emissions. But, the greatest benefit of EGR is actually improved fuel mileage at cruise due to the fact that you're using less fuel to keep the engine running.

So, if anything, by removing the EGR you will run lean under cruising conditions because the PCM will still be trying to trigger your EGR and think that it is running with "X" amount of oxygen entering the the cylinder so it only requires "X" amount of fuel. However, with no EGR you'll really be having "Y" (Y is greater than X) amount of oxygen entering the cylinder and still only that "X" amount of fuel.

Over time, the PCM may correct for the lean condition based O2 readings by changing longterm fuel trims, but this will result in additional fuel being consumed during part throttle and cruising times.



To make a long story short, you're gonna kill your highway mileage and your daily in town mileage will suffer slightly.
 
#11 ·
well it wouldnt be that much less milage. after i removed mine, i still got 280 miles in town which i dont think is that bad at all for this car.
But when i put the injectors in is when my milage went down hill for some reason.
 
#12 ·
280 in town I'd say is great. Also like I said, in town mileage would only suffer slightly because you're on and off the throttle more. EGR is really only utilized when cruising at a constant throttle position.

Also realize that when I said his highway mileage is gonna suffer, I didn't mean like it was going to drop 10mpg. It'd most likely be a 3-4mpg difference if you did straight highway driving, but that kind of stuff adds up over time.
 
#20 ·
You've got to be kidding... It's only routed to one cylinder - 6 and fed by a tiny little 1/2" hole... EGR is a federal band-aid requirement. It's just an attempt to reburn some of the spent exahust. There's no real benifit to EGR will not effect mileage. If it did help the MPG there'd be EGRs for every cylinder...
 
#13 ·
my car w/o egr made 26mpg on the highway. granted i didnt hit boost once threw the full tank of gas. but i did have an exhaust leak and am running rather rich.

i feel the benifits from the egr dont out way the constant heating of the intake air charge. even on my n/a with intake and exhaust i saw a 2mpg GAIN in mpg on the highway. wich is around 25.5mpg with my dad driving(he drives the car harder than i do).

to each their own but i dont run it.

-shane
 
#14 ·
thanks for the ubondence (sp?) of info.

the only reason why im thinking about doing it is because the passed a law taking into affect june that any car 15 yrs and old can get a car show/club plate eliminating emissions on that car and you have to use collector car insurance which is not bad about $300 a year! the only downfall is you can only drive x amount of miles. cough.....just unplug the speedo or roll it back...cough

another thing is im trying to clean up my bay, make it look a little cleaner and such.
so 2-3 miles a gallon isnt really going to kill anything.
 
#16 ·
No, not really since EGR isn't active under WOT. If you're not worried about emissions or gas mileage and want to clean up the bay, go ahead and take it off. You aren't really going to hurt anything in the long run besides Mother Nature.
 
#25 ·
so there really is no benefits to removing it? just "lessens the clutter" if i remove it? IL passed a law that states no vehicle that is NOT OBDII will be tested for emissions after FEB 07. meaning...i have no emissions anymore :)...but if taking it off will not do anything positive...just possibly do something negative...fuck it..i'm leaving the engine bay cluttered
 
#30 ·
same over here, but its 15 years and old you can do a "club car" and pay collector car insurance which is hella cheap ~$300 a year. and you dont have to do emissions. only down fall is you have x amount of miles which is fine just use a differnt speedo........
 
#26 ·
so much dis-information in this thread.

EGR WILL LOWER YOUR EMISSIONS. PERIOD. THe ECU is tuned to run with EGR. Newer cars don't have EGR as it's built into the cam profiles.

Now, if you're running with the stock ECU, you'll run lean during crusing, and the ECU may richen it. What does that mean? It means it richens it over all the fuel maps, meaning BAD MPG. A JDM or standalone won't have that issue.

280 for a tank isn't that good IMHO, if you're not getting over 300 something is wrong (or you're boosting like a MOFO)
 
#28 · (Edited)
Just out of curiosity, what out of what I posted was misinformation and any different from what you just said?

Oh and guys, don't get bent out of shape by the "3-4mpg." That was just an arbitrary figure that you might expect to see. I've never done any kind of testing with EGR systems and these engines, so a real world change in fuel mileage could definately vary. However, removing EGR, at least in theory, should lower your fuel milage under cruising conditions, regardless of how great that loss is.
 
#29 ·
wasn't aimed at you ;)

Emissions stuff is tough on this car, as the ECU is directly tuned to have all these gizmos on it to tweak it. Take it away and it gets confused.

Standalone on the other hand will have zero issues after getting rid of a TON of the emissions equipment...
 
#35 ·
The EGR valve dumps into the surge tank where it feeds all cylinders. Its purpose is to reduce peak combustion temperatures to reduce the formation of NOx emissions under cruise. It also has the rather nice effect of reducing detonation which allows running slightly more advanced timing for better MPG, although it won't help at WOT as already mentioned.

Remove it and the ECU maps will not be correct for cruise, and you will see higher EGTs. JDUB has posted measured EGTs 100degC higher under cruise with EGR disabled. He was also failing AZ emissions until he put it back on.

http://www.supramania.com/forums/showthread.php?t=27185

Newer cars uses VVT to achieve the same effect.
 
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