I have a new EGR question........ Does it hurt to remove it????? Our 97 Tahoe has been having "EGR PROBLEMS" (quoted by a local mechanic shop) and they claim the engine will not run w/out it.... and it has been missing/going dead horribly! Is this correct or are they just dumb asses???

why is an LS1 any different(if it doesn't hurt them)????

Can I take the EGR off of the truck too???

Josh S.

 

well.. not 100% sure on a truck.. but a F-body will run fine without an EGR.

 

TTT..... I'm not sure what would make a difference..... Anyone Know???

Josh S.

 

The EGR is there to prove exhaust gas recirculation. In other words, some exhaust gas is dumped back into the intake, this helps reduce emissions and lower the temp in the combustion chamber, actually helping cool it. The newer LS1 cars 01 and up do this with cam timing.

Sometimes a car will be more prone to ping if the EGR is blocked off in hot weather. My 91 RS pinged badly with the EGR valve was clogged with carbon build up. However, the car ran.

The missing or going dead, sounds like a maybe a vacuum leak. I know on my cars LS1 intake (the one with EGR) it wouldn't take much to get a vacuum leak as only 1 bolt to secure the o-ring under the EGR pipe that goes into the top of the intake.

Good Luck.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 99 Black Bird T/A:
The EGR is there to prove exhaust gas recirculation. In other words, some exhaust gas is dumped back into the intake, this helps reduce emissions and lower the temp in the combustion chamber, actually helping cool it. The newer LS1 cars 01 and up do this with cam timing.

How does it lower the combustion chamber if the air is recycled from the hot exhaust gas?

Sometimes a car will be more prone to ping if the EGR is blocked off in hot weather. My 91 RS pinged badly with the EGR valve was clogged with carbon build up. However, the car ran.

The missing or going dead, sounds like a maybe a vacuum leak. I know on my cars LS1 intake (the one with EGR) it wouldn't take much to get a vacuum leak as only 1 bolt to secure the o-ring under the EGR pipe that goes into the top of the intake.

I agree here. My car didn't idle worth anything when my egr o-ring had a leak
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">

 

There're two things that EGR does. One is the
cylinder temp lowering (which works by decreasing
the energy content of the mix; even though the
gas is hot, it's "cooler" in its total thermal
+ chemical energy content than the same volume
of A+F.

The other thing EGR does, is lower pumping losses.
Some of the cylinder charge is made up of
unthrottled waste gas. This lowers the vacuum
pulled & the intake side pumping energy spent.
This, or that you ingested less fuel for the
same stroke (however you like to look at it),
increases light throttle fuel economy.

If you block off EGR, you should expect a bit
poorer cruise economy. Like that's why you
bought the car.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by The Guy in MY 99TA:
<strong>I have a new EGR question........ Does it hurt to remove it????? Our 97 Tahoe has been having "EGR PROBLEMS" (quoted by a local mechanic shop) and they claim the engine will not run w/out it.... and it has been missing/going dead horribly! Is this correct or are they just dumb asses???

why is an LS1 any different(if it doesn't hurt them)???
Can I take the EGR off of the truck too???

Josh S.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You can bypass the EGR and the computer will never figure it out. Remove the 2 screws the hold the EGR tube to the exhaust manifold. Cut a 1" square by 1'long piece of K&N foam filter material. Put the foam filter material into the tube all the way up to the EGR valve. You can use a stiff wire or coat hanger to feed it thru the tube. Get some 1/4" steel flat stock. Cut the flat stock to the shape of the flange on the exhaust manifold or header where the tube came off. Drill a couple of holes in the flat stock for the screws. Install the flat stock using the stock screws. DONE! The EGR still opens and closes when the computer tells it to so the computer is happy. The exhaust gases go out the exhaust. The EPA might not be happy if they knew you did this. The only other difference is that when the EGR valve opens your flowing filtered air into the intake manifold, not recycled sooty exhaust gases. That sooty crap carbons up your entire intake track. That includes the throttle body, intake manifold, fuel injectors, valves, etc. Isn't that special? We should all give the EPA a round of applause for putting all that sooty crap into our intakes.

 

what Jimmy said, plus

The exhaust gas is actually cools some by the time it's recycled to the intake. The EGR waste gas displaced some of the "air" and reduces the about of oxygen present in the combustion chamber and acts as a "filler", this also helps reduce chamber temp at part throttle. This effects the way the combustion occurs and reduces emissions, mainly NOx I think.

and as the other person said, it sure can help carbon stuff up...

 

Good information. I have LS1 edit on my 98 Z28 right now. The egr code has been deleted, but my egr system is still there until I get the new intake manifold. I have been driving around with the egr wires unplugged to see if it makes any difference and throws any codes. So far no problems. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />