Tube header replacement. EGR concern

[Adam454ss]

I was wondering after Garrett asked if I wanted the EGR left in place or remove when he cuts an exhaust flange for me so I can get a tube header made for myself. If the EGR is done away with would anything need to be done to the ECM or is better to leave it in place. Now here is the real million dollar question. Can someone explain what the EGR is and what does it do? I'm just guessing but is that Exhaust Gas Return??
Thanks for the help

[Audacity Racing]

EGR is the exhaust gas return.


The purpose of EGR is to limit harmful emissions from your car. It prevents the ignition temps in the engine from getting too high where NOx compounds are made.



I really don't think you'll have an issue doing away with it. You may get a CEL over the solenoid or possible emissions catalyst failure, but neither are performance limiting factors. I can't say for certain on the Daewoo ECUs but typically speaking, these types of errors will NOT throw the ECU into fail-safe mode.





Personally... I'd leave it in.

[Adam454ss]

Thanks for the quick response. I will leave it in. Do my part as a "Tree Hugger" to help protect the atmosphere!

[FabricatorX]

haha all of the flanges we cut has it removed. it can be added back in though, just need to mill the header flange is all

[Turtle_Wax]

The egr feeds small amounts of hot exhaust gas into the intake which lowers the combustion temp therefore reduces NoX (nitrogen oxides). Here in the UK we don't check NoX but if your country does then it may fail the emission check if you blank off the egr. As its function is to lower combustion temp you may end up with spark knock (pinking) if the cylinder temps are too high (or perhaps the knock sensor may adjust the timing to prevent it?)

[FabricatorX]

that problem is typically solved in most cases by running higher octane fuel

[Spider]

that problem is typically solved in most cases by running higher octane fuel

That was the "back in the day", non electronic control module days dude.
Back when we dealt with carburetors, soft valve seats, valve adjustments, point gaps, dwell, distributer tweaking and two dollar timing lights.

Nowdays, folks that think high octane is better (for vehicles that are fine with lower octane fuel) actually help make the pump prices go higher.

Nowdays, your just wasting your money when you use high octane gas in an engine that is designed for low octane gas.
And when you remove emission devices from these engines? Your defeating what they were designed to do and changing your engines reaction to your 'change', I.E. pinging, CEL...etc..
I am talking about a factory stock "modern' engine here. And please don't take this personally, OK ?

As far as emissions goes ? California has the most cars and the strictest emission regulations in the nation (possibly the world?)

If a California vehicle doesn't pass the yearly or bi-yearly smog-test? It isn't allowed on the road.
The only way to get around the test would be to relocate to another state. Or country ?

Personally, I won't be doing that. I like it here and have learned to live with the emission laws. It's just the price we pay for cleaner air
and great weather !
Out here we have to take the good with the good.


So, have fun working around your emission's while knowing that "sooner than later" your state (or wherever it is that you live) will follow California's lead.

[FabricatorX]

thank for for that lightshow of knowledge which pertained to nothing of this topic. And yes, the motor DOES in fact re-tune itself depending on what octane, i.e. KNOCK SENSORS. Todays engines and EMS systems are a wonderful thing. no offense, I just dont want false information running around.

[Spider]

thank for for that lightshow of knowledge which pertained to nothing of this topic.

This sarcastic statement has prompted me to write this rebuff.

And yes, the motor DOES in fact re-tune itself depending on what octane, i.e. KNOCK SENSORS. Todays engines and EMS systems are a wonderful thing.

So if the 'motor' re-tunes it'self ? Why would you say "that problem is typically solved in most cases by running higher octane fuel" ?

I just dont want false information running around.no offense,

I am not offended FabricatorX, Its just that this statement is kinda vague. What false information and who is; "running it around" ?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Please note the "Topic" of this thread is;

"Tube header replacement. EGR concern"

EGR does pertain to emissions, do you agree ?

I commented on emissions, removal vs. leaving them in.....Part of the topic.


your quote;
"that problem is typically solved in most cases by running higher octane fuel"
became a statement (that pertained to this thread) and prompted my statement regarding high-octane fuel vs lower-octane
.... Part of the "topic"

So exactly what is the "false information" ?

This is a forum. A place where everyone has opinions.
Most of us respect the opinions of others.
Some are right on and some are way off. It all gets sorted out in the end.
None of us are perfect.

[daewoomofo]

well put spider

[FabricatorX]

With higher octane, the motor can run the proper timing, which means proper combustion, which means lower overall cylinder temperatures. I apologize for coming off as a dickhead (which is what it looked like reading what I wrote).

Jimmy

[Spider]

I totaly accept your apology !

Still wondering why the computer wouldn't also adjust for lower octane gas.
As I have heard that higher octane actually burns hotter and will leave more residue in that process.

[mtlswift]

Still wondering why the computer wouldn't also adjust for lower octane gas.
As I have heard that higher octane actually burns hotter and will leave more residue in that process.

The computer can only do so much before other problems arise. It can't, say, retard spark timing 40 degrees whatever... it's limited to how much it can do, so you can still run into knocking with low octane fuel even though the timing is retarded.
Say you figure out how to retard the timing so much that you won't get knock, you can run into improper combustion processes for the engine which kills power, harms the engine etc. Having spark way too early or way too late can cause piston slap and other things that are bad for the engine.
A friend of mine had an older civic that for some reason was knocking so badly under load (e.g. climbing a 5% grade) that the computer pull back timing to the max that it slowed from 50 mph to 20 mph by the end of the stretch, ~ 1 mile. It was a safety hazard.
High octane fuels burns slower and cooler which is less knock-prone, but that can lead to sooting and carbon deposits when run in cars that are not meant to run high octane fuels. But if you have an older car that knocks on regular, you can run higher test fuel to try to alleviate the problem. It's a synergy thing.