Blocking off EGR

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SyntheticShield

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Among the people that own a Ford Focus, it seems to be a popular thing to block off the EGR if not completely remove it. Im not really familiar with this being of any benefit, never really heard of it being done really until I purchased my Focus.

What are the pro's and con's of doing such a thing aside from the emissions. I think it was on the Lubrizol website that I read that the EGR can lead to more rapid TBN depletion. Does that mean if I (I dont plan on doing so) did so that my oil would stay healthier for longer?

Just looking for some insight, I am curious as to why so many do this cause I just dont see any gains being made from a performance perspective. Thanks in advance.
 
this just reminded me back in the 80s where lots of guys in the states decided to cut off EGR, bypass air pump (or completely cut and crimp off the air pump fitting entirely), bypass the PCV valve, etc.

Why do they do that? I wouldn't wanna know (and frankly I do not care). What benefits do they get? I would say none. Because most engines designed nowadays have already had all the emission components factored into the equation. Taking them off in hopes of making some sort of gains (economic, fuel economy, longer running, performance...) would be minimal at best (most of the case it's gonna make things worse for nowadays engines are computer-controlled??)
 
teres lots of pros and cons.

for general automotive use, the only pro is reduced emissions and the ability to hold a bit higher spark advance.

the cons are that exhaust gas contains little to no oxygen so it occupies space that could otherswise be taken up by fresh intake air. this effectivly reduces youre dynamic displacment.

in racing, n/a engines dont benefit from egr. however egr has a cool ability to hold off detonation.

a high compression n/a engine or a forced induction engine can benefit from egr in the sence that it can allow you to reach higher levels of boost at a gaven octane rating without destroying youre engine.

OR

you can possibly keep the same boost level but step down 1 or more octane grades to save money at the pump.

my take on the situation is to leave the egr alone. youre not going to get any real gains from removing it. however if it plugs up, i wouldnt bother to fix it on a daily driver. only fix it if youre engine needs it for the detonation factor, which 99% of automobiles dont.
 
I used to know a guy who claimed that when he removed the EGR valve from his late 80's Dodge (can't remember year or model now) the engine ran a whole lot better. Now, I haven't really had a chance to experience those improvements for myself, or find out what exactly constitutes "a whole lot better", but that's just one of the claims I've heard. My guess was that maybe the engine was running somewhat on the cool side, and removal of EGR valve got rid of the exhaust gases that were cooling down (or leaning out? But in that case, the engine would have to have been running on the hotter side?) the mixture even further.
dunno.gif

On the other hand, girlfriend's 98 626 threw out a CEL a couple of months back and shortly thereafter idle got quite a bit rough. Local Mazda dealer diagnosed this condition as a plugged-up EGR valve. Folks at a Mazda forum seem to agree. I haven't had the chance to clean the thing out yet (no time, it's a PITA, and doesn't seem to affect the drivability all that much, aside from the CEL that keeps terrorizing my better half).
I recall seeing in various catalogs so-called "air-pump elimination kits" for 5.0L Mustangs. I've never heard of any significant benefits from using one of those.
In short, I'm with Cryptokid on this one: I wouldn't mess with the EGR system either.
 
Thank you everyone for your replies thus far. Keep them coming, I want to get both sides of this as much as possible.

I wasnt planning on doing anything with the EGR other than the consideration of the effect it had on the oil according to Lubrizol. I mean, if it isnt going to adversely affect my vehicle and isnt going to cause it to be a bigger polluter but will give my oil longer life by blocking it off, I might, MIGHT, consider it. But Im with most that have replied already, I just dont think its worth messing with it, at least based on the current information I have.
 
My Granddaughter has a 95 Buick and the "check engine" light came on recently. We had the codes read and it was EGR related. New Focus may do the same thing.
 
My 79 BMW had all the EGR and Air Pump equipment removed.
It was expensive to replace when it went bad and it killed performance so a lot of people yanked'em!
 
The Focus would definately throw a CEL on if the EGR is blocked off. The people I have read about blocking off their EGR have in some cases also had custom programmed performance computer chips added to their ECU that would cause the ECU to ignore the fact that no EGR was present and thus throw no code.

I have a performance chip installed in mine, but Im not sure it would be worth the expense to send it in to have it programmed to ignore the fact there was no EGR present. Seems like a lot of trouble for questionable gains in performance.
 
EGR has a nicely beneficial effect in keeping combustion temps down.

A race, or true non-emissions engine (designed as such) has the opportunity to run leaded fuel which back in the good ol' days allowed tuning parameters that todays cat pee gas won't allow.

Clean it or replace it, and then don't worry about it.
 
quote:
Originally posted by TheTanSedan:
EGR has a nicely beneficial effect in keeping combustion temps down.

A race, or true non-emissions engine (designed as such) has the opportunity to run leaded fuel which back in the good ol' days allowed tuning parameters that todays cat pee gas won't allow.

Clean it or replace it, and then don't worry about it.
Click to expand...
I will probably clean it out. Im not having any problems with it, was just curious because of Lubrizol's mention that the EGR system contributed to more rapid depletion of TBN in an oil. The thought had occured to me that if that were true and there were not serious draw backs I might have considered blocking it off. But Id have to have some really good info on the effects to consider it.
 
quote:
Originally posted by cryptokid:
teres lots of pros and cons.

for general automotive use, the only pro is reduced emissions
Click to expand...
??? Without EGR, NOx is gonna go through the roof when the engine is under load.
 
quote:
Originally posted by brianl703:
By the way, the EGR valve is closed at wide-open-throttle so the WOT performance would be the same with or without the EGR valve.
Click to expand...
I was just going to say, that Brian..you beat me to it. I agree.
smile.gif
 
quote:
Originally posted by 97tbird:

quote:
Originally posted by brianl703:
By the way, the EGR valve is closed at wide-open-throttle so the WOT performance would be the same with or without the EGR valve.
Click to expand...
I was just going to say, that Brian..you beat me to it. I agree.
smile.gif

Click to expand...
I'll third that one.
smile.gif


I didn't know that originally, and I actually deactivated my EGR valve on my '87 Grand Am a few years ago by blocking the vacuum line with a ball bearing (pushed into the line). It made no difference, and I took it out soon after. Kind of like the K&N, which lasted a few months in my car. I'll just blame these (and many other) things on youth!

As for extending oil life: it's possible it might keep the TBN higher, but I don't think it would be a big difference and really not worth the trouble and extra emissions. You could do some UOA's if you're really curious. You'd probably need quite a few to draw any conclusions though.

A buddy of mine disconnected the EGR on his '87 6.2 Diesel and he claims the oil doesn't get black as quickly, but that's a little different since the exhaust is so dirty compared to that on your car.

[ February 04, 2005, 02:19 PM: Message edited by: rpn453 ]
 
Just concuring with the above 3 posts. EGR doesn't effect full throttle runs...it only opens and vents while your crusing around, usually in closedfuelloop modes.

You can see when the EGR vents if you hook up most OBD-II and CAN scanners to your car.
 
You get cleaner charge and less lean. You intake valves will stay clean, you will not be leaning out good air fuel charge with dirty byproducts. You intake charge will also be cooler and more dense.

You normaly can not just block off or remove EGR valves on moder cars. You normaly need an EGR simulator. It basicly plugs into the vechiles harness after block off the EGR. It sends the apropriate signals back to your ECM/PCM so the computer does not know that your EGR is missing/disabled.

These are available for the BUick 3.8 alot of the GTP guys run them along with differnt cams and rockers.
 
A cleaner intake is about the only benefit from removing the EGR. There is a potential problem though. The PCM will set a code if it is disable. One popular thing is to "remove" the code or spoof the sensor. The other thing to do is block the EGR and let the engine suck in air. The problem with this is that the engine is expecting the inert air from the EGR and gives the engine less fuel. Letting the engine breath in air, put unmetered air into the system. This creates a lean condition.

-T
 
You might say EGR knocks off the high pressure peaks (almost). Dulls the fuel "potential", but since fuel today has little "potential", it is no significant detriment to performance.

NoX reduction is the whole point.

Have had several vehicles with up to or beyond 200k (carb'd, non-computerized) and there was not ever a point where removing the EGR (and retuning fuel delivery/ignition timing) was worthwhile on a street vehicle (and tow vehicles with V8-440 & V8-500; GVW at or beyond 14k on both).

A dedicated, "doesn't work for a living" weekend toy car can be a different matter.

For a street vehicle running all kinds of conditions, leave it alone. Just keep to spec (along with new hoses/clamps/fittings), IMO.
 
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