Purpose of the EGR

[ddgsxr504]

Ok I searched the 240sx.org FAQ and then I searched here but didn't get the answer I was looking for.

What is the purpose of the EGR?? I know that it recirculates exhaust gas into the intake mani but is that to warm up the engine quicker or is it to further burn the unused gas in the exhaust flow, or all of the above plus something more??

[jack-pot]

No, the EGR is not to warm up the engine at all? and if you are getting EGR on idle or at WOT you have some issuses with your car. the EGR recirculates exhuast gas back through the intake on when you are cursing around, the EGR is for emissions.

[elwesso]

What it does is it recirculates exhaust gas to lower the combustion temperature... The exhaust gas is the product of a combustion reaction, thus it is inert (will not react in the combustion process)..... This gas replaces air that could go into the combustion chamber, and thus makes the combustion less hot... Nitrous oxide emissions are only produced after a certain combustion temperature, to which i cannot recall....

Anyway, the EGR only comes on during cruising to reduce the amount of emissions... When you are going around town, or are in the gas, it wont be activated...

Your car can run juts fine without it going but it may not pass emissions... It may still pass if your car is otherwise perfect.

[mirra32]

what if you just take off some of the crap...like the metal pipe behind the motor that also connects to the header....can i just take off just that with out having any problems....the pipe along with the little cap looking thing it connects to....i have a 95 motor....

P.S the reason is because its hitting my Clutch M/C a tad....(i'm RHD)

[naed240sx]

Like he said, your car will run fine without it, and will probably make more power and get better mpg. It will not likely pass emissions. You can remove it, but you must get a plate to block the hole that is left behind.

[DjPantsSpecR]

rhd KA? youre nuts dude

you wont make any more power, and im not sure it will actually help your mpg (unless the EGR was malfunctioning and open at times other than cruising)

people sell the block plates for this on ebay, its like almost 20 bucks after all is said and done. just use the gasket to trace out a piece of sheet metal and then lay it down. and cut that metal tube, but keep the nut going into the header and plug it with a nickel or something

[driftin2trance]

rhd KA? youre nuts dude

you wont make any more power, and im not sure it will actually help your mpg (unless the EGR was malfunctioning and open at times other than cruising)

people sell the block plates for this on ebay, its like almost 20 bucks after all is said and done. just use the gasket to trace out a piece of sheet metal and then lay it down. and cut that metal tube, but keep the nut going into the header and plug it with a nickel or something

yea i wont help gas mileage or make power. it has nothing to do with that. the only reason people remove is so it looks cleaner and they worry that crap is going back to the motor. i think its pointless to remove it so i havent.

[ddgsxr504]

Well the reason I ask is because I think it is opening at times other than crusing. Under acceleration my car starts to jerk and hesitate and then dies when I slow down and stop at redlights and stopsigns. (example) I slow down take my foot off the gas and pop it in neutral and then it stutters like it is going to die and some times it does. I restart the car and everything is fine?? I'm not worried about emissions since I am regestered in a state that does't care. So should I take it off or try and trouble shoot and replace EGR components?

[driftin2trance]

if it is giving u trouble than just take it off, there is a write up someplace that has pics and everything. just make sure u block it off.

[DjPantsSpecR]

ddgsxr504, i have a similar problem, but on my auto car, so when it comes down to idle sometimes it sputters enough to die.

its not timing, ignition, aicv, knock sensor, cant find a vacuum leak, so this what im trying next. plug the tube with a nickel next to the exhaust manifold and see if anything changes. this way you dont waste any time removing a lot of stuff like the upper intake manifold, and it will help you diagnose the problem... if it is the problem, then do all the work

[ddgsxr504]

Yea I'll def give that a try. Thanks

[hek1620]

i took everything having to do with this crap off. welded the port on the back of the head shut. cut the two pipes that connect to the exhaust, but since that nut doesn't come off the pipe, i used a metal clothes hanger for material and welded the pipe shut behind the nut. so i could just put it back in. afterwards my sohc DOES make more power. and it DOES get better mileage. just chuck all of that crap if u live in a state that doesn't test.

[Bigvinnie]

ddgsxr504, i have a similar problem, but on my auto car, so when it comes down to idle sometimes it sputters enough to die.

its not timing, ignition, aicv, knock sensor, cant find a vacuum leak, so this what im trying next. plug the tube with a nickel next to the exhaust manifold and see if anything changes. this way you dont waste any time removing a lot of stuff like the upper intake manifold, and it will help you diagnose the problem... if it is the problem, then do all the work

Actually I had this exact problem as well. It defenitely isn't the EGR, but it could infact be the BPT valve. Other than the BPT valve it can be the IACV (Idle Air Control Valve). It can get jammed up from years of use. If you usually feel hesitation or jerking, even having the idle die upto almost 2000RPM it can be the IACV, there are a couple of was to fix this situation.

First you can take your intake off and spray carb cleaner in to the intake system. If that doesn't work than it may need replacement.

It could also be the EGR/BPT but more than likely the BPT since it controls alot of the vacuum function of the EGR valve. I noticed this when replacing the EGR valve with a new one and replacing the BPT vacuum line.

Here is the link to zilvia where we discussed the issue of the IACV.http://www.zilvia.net/f/showthread.php?t=95371

[ddgsxr504]

I thought it might be the IACV but I didn't want to have to take the intake mani off. I'll give this a try and figure it out, thanks again guys.

[Edub1]

The EGR routs filthy exhaust gas back into your intake manifold. They tend to fail because they get caked with carbon deposits and stick open. When this happens, it's the same as having an intake leak. I just didn't want that crud going back into my intake so I disabled mine (in a dream I had) by simply removing the vacuum hose and plugging it with a screw. Now it stays closed unless yours is already caked open. In this case you might have to remove it to clean it or replace it.

[tonynalli]

what i did to block mine off was put a big blob of jbweld on a nickel and use the big nut that was holdign the pipe on and screw the nickle down in hole..works great

[tiger]

well I sawzalled that pipe off about an inch out from the mani and then when I was closing it up I just unscrewed that piece.. stuck a nickel in there and screwed it back on.. walla!

[luna11]

I had a problem with my car surging at about 58mph ...changed plugs, wires...still a problem...then i disconnected the hose and used a screw, just like you did....SURPRISE!!!! runs perfect now!!!!

[420sxse]

Removing the EGR would have to make more power. Think about it: Inert gas in the combustion chamber displaces components needed for combustion...ergo less power extracted because less gasoline reacts. Fuel economy improvement isn't as obvious to me...but I have seen people with emissions components removed state that they get improved mileage.p.s. When I was replacing gaskets last week, I found that where the EGR passage bolts to the intake mani...the bolts were loose! It had to have been sucking a little air. The engine had run fine for four years until last November (major hunting/stalling problems)...they must have worked themselves loose? I've never touched the EGR before.

[crzycav86]

Just an fyi:

Keeping your properly working egr will improve gas mileage.