EGR Mod

[sjrobinson]

I’ve found this interesting a while ago. Keep in mind that certain emissions mods may be illegal in some areas. However, in theory this mod is interesting. I wanna know what you guys think of it.

Heres the link. There are two parts. This is the second but the first part explains the EGR’s function in depth and the electrical.
http://www.autospeed.com/cms/article.html?&A=112730

I’m sure many of you have heard of autospeed.com. I love this site.

Basically this mod would be to improve emissions and increase fuel mileage. Being halfway in the world of amature tuning I see people foolishly block off the EGR. This actually increases NOx emissions and decreases power by causing a hotter combustion. This can also lead to detonation.

The theory behind the EGR Increase mod is to actually let a little more recycled exhaust into the combustion without losing power. This allows for less pumping loss when decelerating with the throttle closed letting you cruise a little farther.

So, I know there are two types of car people-

those who say “if the car engineers designed it that way, it should stay that way”.
And “I wanna mod it to suit my preferences”

What do you guys think of this mod?

Topic

[kevin gosselin]

If the converter can handle it and you don’t trigger an engine code, then go ahead.

Computer use strategy to confirm component do there job. so being said strategy use in 2000 and strategy use come 2015 are not even close to be the same. Now they monitor 02 sensor with every aspect of their wave form. so if you can increase Flow and stay in the limit of what the computer wants to see then you are golden.

What are the limit…. now it’s a programmer job. I wouldn’t attempt to do the mod on a vehicle with already good fuel economy that works great and is fairly new.

If you have access to cheap spare part to prepare your mods. that might turn out to be a good alternative as if you don’t have the result you want. You can put it back stock

[sjrobinson]

Yeah, this is pretty simple. Its just a pot in series with the valve lift sensor. The ECU would see the EGR valve as more closed than it is and think its opening it less than it really is.

I think the o2 sensors would just see a slightly leaner engine, but still within its stoichiometric range. The EGR is only active during deceleration or light acceleration so I’m not sure if the o2 sensors would influence the AFR that much. Am I right in assuming that?

This will be tried on my 97 Accord. A good experimenting car. In the article he used an Insight, with positive results.

Although, I’m not too sure what to do now that cars are getting smarter than their drivers. 😛

[kevin gosselin]

Yep for the age that sound like an upgraded that shouldn’t disturbed anything. The V6 model gummed up overtime and plug the channel from the egr to intake port. just trigger the egr solenoid to see if it stall. If it doesn’t stall, the egr system if plug and should be address first.

I believe you have the best guinea pig model to give it a try anyway.

O2 and EGR monitoring strategy are fairly basic.

EXAMPLE : you 02 sensor could be really sluggish compare to a new one and still would not trigger a light. being shorted or open being a hard fault would trigger the light tho. newer car would look at the oscilliation wave and analyze the upward and downward curve with parameter according to load rpm and such

Good luck and hopefully you can come with positive result

[sjrobinson]

Yeah. My car almost never throws a CEL unless I purposely unplug something. Although I tend to question how efficient my upstream o2 is…

But I’ll give this a try and see how it goes. Right now I’m getting anywhere from 28 to 31 mpg depending on city:highway ratio. Lets see what happens.

Thanks for your input, Kgevil 😀

[Jamie]

The only EGR mod/delete I’ve seen is on the Pomp Dues era VW TDI engines. Guys take them right off, bypass the coolant part of it and get block off plates.

I does serve a purpose but in that particular engine it does a brilliant job of choking the intake so badly that the engine barley runs. Dealers wont clean them either, they push you to replace the intake. Usually it takes a day to clean the entire intake/valve train of soot/carbon and its a filthy job. For a lot of back yard mechanics its enough to inspire them to delete it completely.

[sjrobinson]

Thats interesting. Those are diesel engines that run at higher temps though, right? A quick search shows that its a common mod with many diesels.

What I find odd is that the delete mod is claimed to reduce charge temps. Although from what I’ve read is that the EGR will help reduce detonation by reducing the specific heat of the combustion mixture.

So basically by blocking off the EGR you actually increase combustion temps more than the initial exhaust gas would, right?

[Jamie]

It will certainly raise the combustion temps for sure. But in that era of TDI VW/Audi engine its not enough to cause issues with anything elese if the engine is in good working order. Guys claim to have more umph in that engine after but I’ve never driven a car with the EGR and then without back to back.

If I owned one and I had to clean one again the EGR would come off for good and I would register the car somewear that doesn’t have air care to deal with. It literally shaved years off my life I figure. Even after letting the intake manifold soak in detergent for half a day I still had to scrape the soot out by hand. Cleaning it off the valves wasn’t easy either. I had to rotate the engine and one cylinder at a time while the valves were closed get in there to chip at it, then brush it out. All on the back side of the engine.

A few companies sell carbon remover that’s recommended using as a regular maintenance item. While the engine is running you basicly pour the stuff into the intake and allow it to dissolve the carbon. But it only works if you do it every year, two at the most. Downside is it doesn’t clean the EGR, just the crap the EGR caused to cake up.

I really hope they addressed that issue with the new clean TDI engines. Its an astonishing bit of engineering that engine but time will tell.

[sjrobinson]

I suppose a combo of high engine temps and exhaust soot make EGR a bit trickier to deal with in diesels.

What of egr recirculated from past the cat and particulate filter? That would reduce temps and carbon deposits from the EGR right?

[Author]

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