EGR System Facts

[Strannik]

let's talk technical, don't bring greenies in here
if you care about enviroment so much as they do you shouldn't be driving performance vehicle

now back on topic:

1) You seem to be ignoring my point that JDM supras don't have EGR. I'd like to see some explanation to that.

2) EGR decreases the combustion chamber temperatures, which is decreasing the power and MPG

Confirmation is on the website you list in links:
http://www.misterfixit.com/egrvalve.htm

The automotive engineers figured that they needed to do something to lower the peak combustion temperatures which only occurred under certain high load driving conditions. They figured they could do so at the expense of power and fuel economy but what the heck, ya can't have everything! If they could only add something to the combustion chamber that would act like sort of a fire extinguisher to cool the combustion temperatures that would do it.

So it's a catch 22 - whatever you do you lose performance. In this case i would get rid of EGR just because it's another part that can go wrong.

3) Yeah i agree, it doesn't operate at idle, i was wrong here.

4) Here is the quote from another website you gave:
http://www.asashop.org/autoinc/dec97/egr.htm

Even if the car appears to run well, excess smog is being produced. An EGR failure will not only cause excess NOx, back up strategies will often entail enriching the mixture or retarding the timing. This in turn increases HC and CO emissions. Even if you don't see it on a 4-gas exhaust analysis test, the emissions are being created and the catalytic converter will not always cover them up.

If you can't see the difference on analysis then what's the point of it?

Bottom line is: the only place where you will not pass the test w/o EGR is California. Main reason why people remove EGR is because it causes carbon build-up on the intake.

Please comment on JDM supras not having EGR