running 3.4 DOHC with EGR valve unplugged

[95-GTP-3.4-DOHC]

WARNING: Do not unplug your EGR without disabling it in the ECM. It will screw with the ECM. Any performance increase you think you get is in your head. Turning off the EGR makes no noticable increase in power, but will help you keep the power by not coating the intakes and intake valve with carbon deposits. I leave this thread here as an example of what an arrogant idiot sounds like. - SappySE107

Edit again. The only way you are gonna see a power increase from removing the EGR is if it was leaking. Then, a new stock EGR would give you the same results as removing it...other than your ECM is gonna be pissed at you for not disabling it. -SappySE107

I've been running my 3.4 ever since I got it 5 years ago, with the EGR valve unplugged. It makes noticeably more power that way. Has anyone else tried this ? I've done this with many previous cars I've owned as well, and they all ran better too. I see no reason to put exhaust gas back in the intake tract, from a performance standpoint.

[z34phoenix]

the diff in perf is not even 2-3hp there is no way for you to have felt it. sorry.

runing without an EGR on modern cars that acount for it in their programing is dangerous! the egr puts small amounts of exhaust gas in the intake charge so that it lowers combustion temps. this reduces engine detonation and Knock. if you remove it, the cars programing will still think its there and you will be having increase detonation and KR. KR retards ignition timing and that severily reduces HP.

In theory removing the EGR is a good one, ( more fresh clean air in the cylinders) but you need to be able to retune the car once it has been removed. I have done this to my Z. I used my DHP Powertuner to recalibrate all the fuel and spark curves. Additionally i have a gauge i run while driving that allows me to watch and monitor my KR levels.

if you insist on runing the car without the EGR the one thing i will recomend for you is the following:
-dont ever run less then 89 gas (91 recomended)
-check your plugs... if any white is on the electrodes go to a colder plug
-run a 180* thermostat and keep your coolng system in top shape.

[95-GTP-3.4-DOHC]

Well, I was asking for others who have also done this, but since you replied:

dude, seriously, in the past 5 years I logged 63,000 miles on my 3.4 DOHC with the EGR valve electrical plug pulled. The car runs WAY better.

the purpose of the EGR is specifically to reduce NOX EMISSIONS- that is OXIDES OF NITROGEN, or NOX- the main component of car exhaust that creates photochemical smog in major cities and urban areas. NOX is created by unburned fuel in the engine, they found that by decreasing combustion temps, less NOX is produced.

that's the ONLY reason an EGR valve was ever designed, no other reason- it's a PITA emission device, nothing more- the Japs and Germans don't even use them on their cars sold outside the USA, what's that say ?

introducing exhaust into the intake stream, dilutes the mixture- engines are made to run on fuel, not exhaust diluted fuel. Sure, it reduces combustion temps, but that's because it's not getting as much fuel as it should. You could throw powdered flour in too and reduce combustion temps as well, the engineers just happened to use exhaust gas, because that's what is available under the hood in the car, to get combustion temps down.

I disable the EGR and run PREMIUM FUEL, there is no spark knock, and part throttle driveability is SUPERIOR.

Before you diss the idea, you should TRY IT FIRST. Find a long hill and drive up it with your car at part throttle- go back to the bottom, pull the EGR plug, and drive up it again. It's a mighty s-hit more difference than 3 HP ! It's like night and day. With the EGR, the engine will require more throttle angle to go the same speed.

If it wasn't for USA emission laws, there would be no EGR valve on cars at all- over in Japan, Asia and Europe, they don't even use an EGR- because it's not required, their emission laws are more lax. So I rest my case.

Hot rodders have been removing and plugging EGR valves since they first came out on cars in 1973- where the heck have you been ? I've got the notion you're not old enough to know that.

The spark and fuel issues are not a problem, with the computer, it will automatically adjust the timing and fuel, with EGR removed, but it will kick a code, which you can just ignore. I've logged over nearly 400,000 miles on 5 different vehicles, all with the EGR disconnected. So this is from experience, not doing it just now- we've been shutting off EGR's since the 1970's.

keep in mind at wide open throttle and idle, most EGR valves SHUT OFF for smooth idle and better WOT performance. What's that say ? If you opened an EGR valve forcibly with your fingers on the older cars, while the engine is running, it STALLS THE CAR, by diluting the mixture. Imagine what it's doing to your engine performance when it is opening then. How can EGR be a good thing ?

[95-GTP-3.4-DOHC]

more:

EGR decreases the efficiency of gasoline engines via a few mechanisms:

Reduced intake charge density. EGR tends to heat the intake charge. This means a bigger piston or stroke must be used to induct the same amount of fuel and air mixture. This results in a bigger and heavier engine.

Reduced specific heat ratio. A lean intake charge has a higher specific heat ratio than an EGR mixture. A reduction of specific heat ratio reduces the amount of energy that can be extracted by the piston.
EGR is typically not employed at high loads because it would reduce peak power output, and it is not employed at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle.

Early EGR systems were relatively unsophisticated, utilizing manifold vacuum as the only input to an on/off EGR valve; reduced performance and/or drivability were common side-effects. In the past, a meaningful fraction of car owners disconnected their EGR systems. Some still do either because they know EGR reduces power output, causes a build-up in the intake manifold in diesel engines, or know that the environmental impact of EGR's outweigh the NOx emission reductions. Disconnecting an EGR system is usually as simple as unplugging an electrically operated valve or inserting a ball bearing into the vacuum line in a vacuum-operated EGR valve. In most modern engines, disabling the EGR system will cause the computer to display a check engine light.

[bszopi]

You need to step off your high horse and quit playing the age card. Its getting kind of old...

As far as disabling the EGR, its not something new you decided to "let us in on". A quick search pulled up threads from March 04 (probably would have gone back further if we hadn't lost a ton of info from our previous joint venture) about people disabling the EGR. But, what differs from what you have posted and what the majority of the people around here have posted is they disable the circuitry in the programming instead of just unplugging it.

You yourself stated you can get an SES, but you just ignore it. Well, that's all great, but what if something else sets the SES after the EGR already has? Hope its nothing major, because there is a good chance you will never know about it. Or, you will just always think its due to the EGR, when in fact it could be something completely different, potentially leading to engine failure. Extreme case? Sure... But it could happen.

So, the most ideal method is exactly what z34phoenix said. Turn it off in the programming. Do you need to change the fuel and spark maps? Maybe, maybe not. But I can guarantee that you can change the fuel and spark maps at the same time and see an even bigger improvement in power and/or fuel economy.

And finally, I'm glad to see you are so environmentally freindly. Hey, you're old... fuck the environment, right? Who cares about it, cause you'll be dead before it matters anyway. Who cares what other countries are doing to help destroy the environment. We in the US are depriving you of a couple HP in order to help lower pollution levels. Gee, sorry about that.

[HayesPerformance]

You MUST have you EGR deleted from your programming for the vehicle to run proper.

If you lived here I got a Snap-on full engine systems scanner that would show you WHAT is happening to your engine by running with it unpluged AND NOT changing your programming to allow for this change.

YOU CAN run without a EGR but NOT without getting a chip to delete it from the ECM operating systems.

[95-GTP-3.4-DOHC]

[QUOTE=bszopi;330114]You need to step off your high horse and quit playing the age card. Its getting kind of old...

As far as disabling the EGR, its not something new you decided to "let us in on". A quick search pulled up threads from March 04 (probably would have gone back further if we hadn't lost a ton of info from our previous joint venture) about people disabling the EGR.


read the OP, it's looking for others who have tried disconnecting EGR- obviously you haven't

age has nothing to do with it- EGR's are an IQ test, if you're still running one on your DOHC, you flunked

now, don't blame me for your lack of experience- I've been plugging EGR's for 25 years now, and it works wonders

perhaps instead of "looking it up" since 2004, you should put down the keyboard, and pull the EGR plug on your DOHC and take it for a ride, and do a before/after test-epiphany will strike

I noticed none of the more knowledgeable guys here who helped me with the timing info, are sharing your opinion- it's an f-ing emission device, the kids who soup the ricewagons up, that's the first damn thing they block off

[95-GTP-3.4-DOHC]

You MUST have you EGR deleted from your programming for the vehicle to run proper.

If you lived here I got a Snap-on full engine systems scanner that would show you WHAT is happening to your engine by running with it unpluged AND NOT changing your programming to allow for this change.

YOU CAN run without a EGR but NOT without getting a chip to delete it from the ECM operating systems.

thanks for the advice, but I've been running it that way for 65,000 miles, and it runs MUCH better, just kicks a code and check engine light, and requires premium gas

[95-GTP-3.4-DOHC]

And finally, I'm glad to see you are so environmentally freindly. Hey, you're old... fuck the environment, right? Who cares about it, cause you'll be dead before it matters anyway. Who cares what other countries are doing to help destroy the environment. We in the US are depriving you of a couple HP in order to help lower pollution levels. Gee, sorry about that.

pollution- well if you want to make HORSEPOWER, you're going to have to make some smoke- funny how we don't see Top Fuel, Funny Car, or NASCAR racers using an EGR and catalytic converters, gee, wonder why ?? i.e. if you wanna make an omelette, you gotta break a few eggs- I'm starting to realize why you're stuck running a 15 second car, you're scared shitless to modify anything radically in any way

the energy, cast iron, plastic, pollution, labor, etc. required to make and install all those EGR valves, put more pollution into the air during mfg., than all the EGR valves removed while running on a car- EGR valves are cast iron, you know how much coal and oil and electricity is needed, to take iron ore, and make it into cast iron molded parts ? And they had to make millions of them, for all these cars- so wake up and smell the coffee, they don't even run EGR in Europe, Japan, or Asia- the EPA and DER requires EGR valves to sell new cars here- it's a hoax- and its only sane use, is the heavily populated city areas with smog problems

next you'll be telling me, run 2 converters instead of just one ? do you want the car to actually run ? or just be enviro-friendly ? well if you want to be enviro-friendly, ride a bicycle. And if you think your car with EGR is so much cleaner than mine, start it inside your garage and close the door, see what happens to you- if you think that EGR is making your exhaust "clean", you've really taken the enviro-bait hook, line, and sinker- heck you swallowed the pole too

not everyone lives in a shithole city, where 10 million people live on top of each other and breathe their own waste- I live in a suburban/rural area- our air is CLEAN- I don't need inner city emission devices on my car

[dohcfiend]

the best way to remove the egr i know of like some1 else stated is to have some1 take care of it in the ecm to get rid of the ses light, unplug it and block it off.

with it unplugged, the ecm will know it isn't there and probably scale back timing accordingly allowing you to run standard fuel. but i wouldn't advise blocking it off and leaving it plugged in. but hey, if it isn't giving you any trouble then go for it. there may be a little boost(in theory) with the better fuel and the egr-on timing. can't say for sure.

[bszopi]

You really have a fucking attitude problem. And you are talking this way to the guy who runs the site (oh yeah, that's me). And for your information, I don't own a DOHC and my EGR is unplugged. Any other brilliant shit you want to talk? Keep it up and you won't be coming back...

[95-GTP-3.4-DOHC]

the best way to remove the egr i know of like some1 else stated is to have some1 take care of it in the ecm to get rid of the ses light, unplug it and block it off.

with it unplugged, the ecm will know it isn't there and probably scale back timing accordingly allowing you to run standard fuel. but i wouldn't advise blocking it off and leaving it plugged in. but hey, if it isn't giving you any trouble then go for it. there may be a little boost(in theory) with the better fuel and the egr-on timing. can't say for sure.

what I found was, every car I unplugged the EGR on, has better driveability and requires less gas pedal to go the same speed- due to the denser mixture- except my newest car. This really helps when you have the wife and kid in the car, and a trunk full of luggage. Part throttle with EGR just seems soggy to me, on every car I've had but one. I believe they've finally got the EGR figured out on the newer cars, because on our 2002 Saturn wagon with Ecotech 2.2 liter, I didn't have to disconnect it. It has plenty of pep leaving the EGR hooked up. But this GTP and our 2 previous Saturns with 1.9 DOHC 4-bangers, they really suffered with the EGR- all 3 felt like 10-15 HP more at part throttle at least, with it blocked. With EGR on, all 3 cars had a spongy-ness in the gas pedal when EGR opened, requiring more gas pedal to make the car go. With EGR shut off, I just rest my foot on the pedal, and the car is flying. Being the EGR shuts off at WOT on many engines anyway, it usually doesn't affect WOT much, or at all. That's how the Saturn EGR worked. But perhaps the 3.4 DOHC EGR is more sophisticated and still meters exhaust gas at WOT, I see 3 solenoids on it, for various operating modes.

The car definitely has more snot with EGR off.

ps- check out cranking compression test in other thread I posted, before firing it up, one hole was down at 50 psi- but "came in" later after it ran a while.

[bve32k]

Now for my experience with unplugging the EGR. I have a DOHC and I unplugged the EGR from the car and it ran like crap! And yes I do run premium fuel.

I had Ben program me a chip so the ECM thinks that the EGR is not there. I notice no difference in performance. I am sure if it was scanned on a computer there would be very little difference in performance, but not night and day! Not even close!!

[Carlspike]

You have to install this http://kalecoauto.com/index.php?main...products_id=41 when unplugging your EGR valve if you want a performance gain.

[SappySE107]

Closed.