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Discussion Starter #1
Since this is such a popular topic recently, i was wondering if there are any ill effects after removing the EGR system from the car?
 

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yeah, you won't pass CA smog if your EGR isn't functioning right.....but then again that happens with most BPU mods

Ting
 

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If this makes any difference, I don't think the Japanese model has a EGR valve at all.

Later, Steve
 
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It's hard to say if anything bad will happen or not. The fuel maps are calibrated assuming a functioning EGR. OTOH, many guys are running around with blocked off EGR.

I seem to recall stories of a few engine failures attributed to disc. EGR back in the day, but who knows what really caused the problems. You might want to post this question on the mkiv.com list, I'm sure many will respond.

Bob
97 6-speed
 

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The consensus of the proven experts on the MkIV list is that there is no downside to the EGR mod. Some used to suspect that there MIGHT be a downside under the right circumstances (I don't recall off hand exactly what those circumstances were), but in the past year or so they have reached the conclusion that there is no downside.

SP also gets rid of the EGR gear as part of a single install. IMO, that is one of the strongest indicators that it's okay to do it.

Steve

Bob said:
It's hard to say if anything bad will happen or not. The fuel maps are calibrated assuming a functioning EGR. OTOH, many guys are running around with blocked off EGR.

I seem to recall stories of a few engine failures attributed to disc. EGR back in the day, but who knows what really caused the problems. You might want to post this question on the mkiv.com list, I'm sure many will respond.

Bob
97 6-speed
 
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It will increase NOx emmisions, and reduce THC emmisions. You can pass smog tests without a EGR, just requires a different approach. I passed a 1987 Grand National with no EGR and a bunch of mods just by leaning it out.

If you have both cats still in, I'd think it should pass. If it doesn't initally, you could tune it to pass.
 

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Uhh.... I meant no performance or durability downsides. You may very well be able to get more THC out of the pipe if you disable the EGR, but I haven't tested. Just don't hit it too many times in a row until you figure out just what you're getting. :)
 
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THC as in Total Hydrocarbons not Tetrahydrocannabinol. I chuckled a bit too first time they told me I failed THC. I was like "did you test my car or did I pee in a cup and not remember?"
 

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The job of the EGR is to reduce NOx. Nitrous Oxides (NOx) is the main polutant in smog. To reduce smog the EGR takes some of the exhaust gasses and put its back into the intake manifold. therefore lowering engine temps and reducing NOx gases. Most of the newer cars nowadays burn so clean that they dont even need an EGR to pass emmissions ( 01 and above LS1s and the IS 300 for example) They test for NOx on a roller dyno (IM240 test). The EGR does not really effect your cars performance at WOT cause it is only design to work mainly when you are cruising, where most of the nox is being omitted.

My guess why people do the EGR mod is because it cleans uo the engine bay up some and its 1 less thing to hook up on the exhaust
 

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Discussion Starter #18
G said:
To reduce smog the EGR takes some of the exhaust gasses and put its back into the intake manifold. therefore lowering engine temps and reducing NOx gases
I thought the main point of the EGR mod was to lower the temps in the back cylinders (where the EGR system sits). Now that doesn't seem to make sense that with the EGR system in place it would lower engine temps by placing HOT exhaust gasses back into the cylinder.

Thanks for all the replies. I am getting the idea that the EGR mod has no downsides in regards to engine longevity.
 

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The job of the exhaust gas is to take up space in the combustion chamber. If there is no EGR there, the cylinder would fill up with alot more 02 and therefore causing a bigger bang witch equals to more heat, creating NOx. When the exhaust goes back into the intake manifold through that little hole, it cools down quite a bit and would take up enough airspace so where the combustion chamber temps dont get as high to where it creates NOx. Remember, this mainly happens when you are cruising down the hwy at a light load on the motor, so it wont really effect your WOT performacne.
 
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