breather filter on egr

[mp3-79bronco]

well my mani doesn't have a fitting for the egr, and i cant find any fittings to even get welded on, so i'm looking for a way to cancel out the cel for the egr

i searched and found that some people are having success using a breather filter on the egr line...

i was wondering how many of you are doing this and are you having any problems?

[MSpeedFreak03]

from what i understand most of us just delet the EGR valve when we upgrade the intake manifold... i dont know what kind negatives consequences there are from doing it but im not an expert!

[magnumP5]

Personally, I believe that because the car came with and it set for an EGR system you should find a way to keep it. A lot of people swear this doesn't cause any problems but by adding a breather filter you will be allowing unmetered air into the engine. The EGR is also used as knock prevention by keeping combustion temperatures down. FWIW, I've switched to the 626 IM and I just got the corresponding EGR tube to go with it. When I upgrade again to a sheet metal intake manifold I will still be keeping my EGR. I say get a fitting welded on and use a corregated gas line as the EGR tube.

[MSP_4_CODY]

im running a breather filter, no problems so far!

[mp3-79bronco]

i cant find any fittings to use lol its the obx mani so i need a stainless steel fitting.. id like to keep it functional but ill do the filter if i cant... also the exhaust gas isnt metered

[magnumP5]

i cant find any fittings to use lol its the obx mani so i need a stainless steel fitting.. id like to keep it functional but ill do the filter if i cant... also the exhaust gas isnt metered
Look up what the EGR actually does before correcting people. Yes, exhaust gas isn't metered but your intake air most certainly is. The stock ECU's are tuned around the fact the EGR valve is present. The EGR recirculates exhaust gas back into the intake manifold to lower combustion temperature and to burn off some extra pollutants. The ECU is aware of this and thus is tuned appropriately. When you just put a breather filter on the pipe what happens when the valve opens? That's right, you let ambient air in - leaning out your air/fuel mixture and increasing combustion temperatures. The air is unmetered because it is entering the intake track post-MAF and therefore it is not considered when the ECU adds fuel.

All-in-all, these cars are meant to run with an EGR. There is little-to-no performance increase that would result of it either. It's just not worth it. Also, IIRC the fitting is a 1/2" NPT male fitting. It should be pretty easy to find one of those in SS.

[mp3-79bronco]

so i can just go to lowes and get a stainless steel 1/2 pipe and cut one end off and have it welded to the mani and use corrugated tubing to hook to the manifold?

[magnumP5]

1/2" NPT. You have to make sure it has the correct threading. If anything remove your EGR tube or go grab one from a junk yard and test it out.

[jamesk]

Personally, I believe that because the car came with and it set for an EGR system you should find a way to keep it. A lot of people swear this doesn't cause any problems but by adding a breather filter you will be allowing unmetered air into the engine. The EGR is also used as knock prevention by keeping combustion temperatures down. FWIW, I've switched to the 626 IM and I just got the corresponding EGR tube to go with it. When I upgrade again to a sheet metal intake manifold I will still be keeping my EGR. I say get a fitting welded on and use a corregated gas line as the EGR tube.

Id have to agree with Magnum.Putting a breather filter on egr is an easy way out of the problem, but it is not a fix.

The egr should be connected correctly, unless you remove the entire system and tune the ecu not to use it. Throwing a breather filter on just allows unmetered air into the system rather than the exhaust gases.

Thats not the right way to fix it.

[mp3-79bronco]

i really still dont see why it wont work right i mean you even said that the exhaust gas is unmetered, so when it opens the valve air is still going in just not hot air from the exhaust, and if its function was to cool, would not the colder air make it cool better? i just dont see why it would matter if the air came from the exhaust or outside? temp is the only difference i can think of between the two...

[magnumP5]

You're not following this. Exhaust is just that - the result of the chemical reaction of gasoline and air. Exhaust is not air, at least not if the engine is running rich or stoichiometrically (14.7:1 for gasoline). Exhaust gases are usually a combination of hydrocarbons (HC, unburned gasoline), carbon dioxide, carbon monoxide, nitrogen, nitrogen oxides (NOx gases), etc. Combustion processes are the hottest during stoichiometric reactions (ie 14.7 parts air to 1 part gasoline). By recirculating exhaust gases (not air) you're effectively richening the mixture by displacing intake air. This also serves to burn up some of those nasty exhaust gases I mentioned above from the previous process. Intake air temperature has little to do with the temperature of combustion.

However, the point you aren't getting is that the ECU was tuned to work with the EGR valve. It anticipates exhaust gases being recirculated, not extra ambient air entering from the engine bay.

There's just no good excuse for not running a true EGR line.

[mp3-79bronco]

okay i follow you now, thanks ill be sure to go look for a fitting and get it welded on

[MSpeedFreak03]

wow that really helped me understand the EGR process more... and thats why when i get my intake mani i will have the EGR tube with the new setup!

[mp3-79bronco]

does it matter if i hook the egr to the downpipe, or the manifold?

[magnumP5]

Shouldn't matter as long as it's not after a cat. Something tells me that i would be easier to have it running off the manifold (shorter tube) and that running it off the downpipe may interfere with turbo exhaust flow (you want this as fast and free flowing as possible).

[mp3-79bronco]

hey i just had a idea...since i have a 2.5 inch downpipe that goes into a 2.5 inch catless midpipe can i just get a adapter and use the blocked off o2 spot in my midpipe and go corrugated tubing from there to the egr? itd be a lot cleaner looking and is about the same distance

[magnumP5]

You could I suppose but that seems like an aweful lot of hose. I also don't know how the ECU will like that. The EGR CEL gets thrown when the EGR boost sensor does not detect a change in vacuum when the EGR valve is opened. Anyhow, why aren't you going to use that O2 sensor port? Wouldn't you want the first O2 sensor in the manifold, a wideband O2 sensor in the downpipe and then the second O2 sensor in the midpipe?

[Shadow102]

first off the EGR has absolutly ZERO to do with knock prevention. The EGR does not function at WOT or at idle and only at partial throttle during cruising speeds. Adding a little atmospheric air at light cruising speeds will not hurt the engine unless its unfiltered. Also an EGR does in fact meter air to a certain extent it knows when there is flow through it. On top of all this the ECU does compensate for what is ingested through the EGR. You forget there is a O2 sensor placed in the manifold that tells the ECU what the engine is ejecting and compensates accordingly. All exhaust is not created equal so the O2 still has to compensate whether its fresh air or exhaust air. All in all the only thing an EGR is good for is to cut down on NOx during light throttle/cruising speeds (ie what people drive at most of the time)...

The best way i have heard this put is you wouldnt stick a hose up your butt and plumb it to your nostril would you? why would you make your engine do the same.

[BlkWidow]

after reading this, now i have to find a welder to do my pipe hook up(bang).

[mp3-79bronco]

another benefit to me is that the midpipe is not stainless so i can just get a regular steel fitting and I can mig it on at school (we dont have a way to weld stainless) so id have to go somewhere for that...i can also put the nipple directly under it thus making the hose shorter than stock...

oh and my midpipe has the first o2 directly after the turbo, and the second at the bottom before it goes into the midpipe... there is no bung in the manifold

[magnumP5]

first off the EGR has absolutly ZERO to do with knock prevention. The EGR does not function at WOT or at idle and only at partial throttle during cruising speeds. Adding a little atmospheric air at light cruising speeds will not hurt the engine unless its unfiltered. Also an EGR does in fact meter air to a certain extent it knows when there is flow through it. On top of all this the ECU does compensate for what is ingested through the EGR. You forget there is a O2 sensor placed in the manifold that tells the ECU what the engine is ejecting and compensates accordingly. All exhaust is not created equal so the O2 still has to compensate whether its fresh air or exhaust air. All in all the only thing an EGR is good for is to cut down on NOx during light throttle/cruising speeds (ie what people drive at most of the time)...

The best way i have heard this put is you wouldnt stick a hose up your butt and plumb it to your nostril would you? why would you make your engine do the same.
http://en.wikipedia.org/wiki/Exhaust_gas_recirculation

Yes, the EGR is primarily an emissions-reducing device. It does, however, serve other purposes (such as reducing combustions temperatures, which, if too high, can lead to detonation). Yes, the ECU relies on the primary O2 sensor readings but it also works in conjunction with the MAF, which reads the amount of air entering the engine. If the ECU could work solely off the primary O2 sensor there wouldn't be any "System too lean" codes thrown due to vacuum leaks.

Also, the EGR does not "meter" in a controlling sense in that the flow is only metered based on the flow velocity and the diameter of the hose. The only "intelligent" thing about the EGR system is the EGR boost sensor which reads changes in vacuum to determine whether the EGR valve is open or not.

Still, the one fact everyone keeps forgetting is that there is NO proof that removing the EGR valve and/or plugging the line has any appreciable positive effects other than cleaning up the engine bay. There's simply no reason to remove it.

[mp3-79bronco]

well i think im gonna go with my last idea, weld a nipple to my midpipe directly under the spot where it goes to the intake that way i can run a short line straight up to the manifold

[Shadow102]

The EGR is never used to prevent detonation...it is and always has been since it was inveted used as an emissions control device which has been switched back and forth with the use of an air pump...mazda has done it before. And your right the engine doesnt rely solely on the O2 sensor but it does use it to compensate during regular driving aka the only time the EGR opens.

And your right there is no proof of it having a performance gain because there is none most dont build engines to operate at peak performance during cruising speeds, but in instances like not having an EGR bung on the manifold or not having a correct tube for the EGR its an acceptable option...that and it keeps carbon out of the engine as well


http://en.wikipedia.org/wiki/Exhaust_gas_recirculation

Yes, the EGR is primarily an emissions-reducing device. It does, however, serve other purposes (such as reducing combustions temperatures, which, if too high, can lead to detonation). Yes, the ECU relies on the primary O2 sensor readings but it also works in conjunction with the MAF, which reads the amount of air entering the engine. If the ECU could work solely off the primary O2 sensor there wouldn't be any "System too lean" codes thrown due to vacuum leaks.

Also, the EGR does not "meter" in a controlling sense in that the flow is only metered based on the flow velocity and the diameter of the hose. The only "intelligent" thing about the EGR system is the EGR boost sensor which reads changes in vacuum to determine whether the EGR valve is open or not.

Still, the one fact everyone keeps forgetting is that there is NO proof that removing the EGR valve and/or plugging the line has any appreciable positive effects other than cleaning up the engine bay. There's simply no reason to remove it.

[dominoy2k1]

on my first turbokit i just left tubing disconnected and i never got a CEL due to egr.

[Wagonbacker9]

the only rebuttal I have in support of putting a breather on the EGR, is that leaning out the MSP tune might actually lead to a better (read as more efficient) tune. Its not controlled, so I don't know if it would actually work, but bumping the AFRs a bit might actually be a good thing as far as the stock computer is concearned. I'd love to see wideband results with a factory setup EGR and one with a breather on it.

[Shadow102]

the only rebuttal I have in support of putting a breather on the EGR, is that leaning out the MSP tune might actually lead to a better (read as more efficient) tune. Its not controlled, so I don't know if it would actually work, but bumping the AFRs a bit might actually be a good thing as far as the stock computer is concearned. I'd love to see wideband results with a factory setup EGR and one with a breather on it.

wouldn't matter. The MSP runs pig rich at WOT the EGR doesnt function during that point.

[Wagonbacker9]

but what about part throttle conditions? I apologize, I don't know how the MSP ecu runs under different loads, I just know it runs rich.

[magnumP5]

on my first turbokit i just left tubing disconnected and i never got a CEL due to egr.
That's because the EGR could still open and cause a change in vacuum. You only get a CEL from plugging the EGR or removing it.

wouldn't matter. The MSP runs pig rich at WOT the EGR doesnt function during that point.
Exactly. If it does lean out the air/fuel mixture, it does it during all the wrong times.

[mp3-79bronco]

well i found a 1/2 corrugated gas line in my shop so all i need to know now is the size of the fitting that goes to the intake manifold

[magnumP5]

^^^ I'm pretty certain you need a 1/2" NPT male fitting for the intake manifold and a 1/2" NPT female fitting for the exhaust manifold.

[mp3-79bronco]

cool, this thread needs to be stickied... lots of usefull info here

ill do this sometime next week and let yall know how it works

[Shadow102]

but what about part throttle conditions? I apologize, I don't know how the MSP ecu runs under different loads, I just know it runs rich.

nothing that will be noticeable or really make a difference.

[Mutmatt]

i didn't read the 2ng page but the egr also serves a purpose of lowering cylinder temps because the exhaust gas is not combustible there for less of a bang... it is tuned that way and it does not affect the hp. It is used to protect the engine.

[Wagonbacker9]

i didn't read the 2ng page but the egr also serves a purpose of lowering cylinder temps because the exhaust gas is not combustible there for less of a bang... it is tuned that way and it does not affect the hp. It is used to protect the engine.

this has been covered, but never hurts to hear it again... if enough ppl agree, it might be believed.

[Mutmatt]

or just known... :P

[Wagonbacker9]

you know as well as any, there is always someone who knows better than everyone else...despite what logic, physics, or what have you tells them...

[Mutmatt]

opinions are like butt holes... every one has one and they stink.

[Shadow102]

i didn't read the 2ng page but the egr also serves a purpose of lowering cylinder temps because the exhaust gas is not combustible there for less of a bang... it is tuned that way and it does not affect the hp. It is used to protect the engine.

The egr has never been used as an engine protection device. It has always been an emmisions control and only works during cruising light throttle where lower combustion temps will lower your NOx

[RABID_MP5]

Along Magnum's train of thought, if you do decide to pull air thru the EGR - What if you obtain the filtered air from the intake tract, somewhere between the MAF sensor and throttle plate? Then at least the MAF would be accurately measuring the intake charge and its corresponding oxygen quantity. (The argument of whether you should do this remains.)

[Wagonbacker9]

Along Magnum's train of thought, if you do decide to pull air thru the EGR - What if you obtain the filtered air from the intake tract, somewhere between the MAF sensor and throttle plate? Then at least the MAF would be accurately measuring the intake charge and its corresponding oxygen quantity. (The argument of whether you should do this remains.)
you would effectively be plumbing the intake it to itself.... may as well cap it off and save the hassle.

[RABID_MP5]

I have it blocked off (ie with a solid sheet sandwiched on the gasket)and my CEL is always on (P0401) due to the ECU detecting the lack of flow thru the valve. My main goal is to never have to clean/replace that valve again.

[Wagonbacker9]

I have it blocked off and my CEL is always on (P0401) due to the ECU detecting the lack of flow thru the valve. My main goal is to never have to clean/replace that valve again.
(shrug) Whatever works for you. The CEL would bother me....

[Shadow102]

Along Magnum's train of thought, if you do decide to pull air thru the EGR - What if you obtain the filtered air from the intake tract, somewhere between the MAF sensor and throttle plate? Then at least the MAF would be accurately measuring the intake charge and its corresponding oxygen quantity. (The argument of whether you should do this remains.)

If your that anal about it sure but really not nessecary.