The Egr Block Begins?

[jibby]

These discussions are very interesting, and my understanding to this point about the EGR function is that:

Having the EGR -will keep the intake much cleaner, helps control knock sensors and pre-ignition firing. Heats up intake flow which robs a little HP, helps with emmissions.

Not having the EGR - Engine intake gets dirty and buildup occures, hot gases no longer flow into the intake which allows for cooler flow and makes for a little more HP, reduces risk of vacume leaks, cleaner engine bay, check engine light comes on.


It almost sounds to me like it is better to have it then to not.. I was looking into ways before this discussion to keep the EGR intact with the S&S Header install. I was seriously considering removing the heat sensor that goes into the stock header/exhaust manifold and drill, weld and remount that same heat sensor in approx. the same location on the new S&S Header, in order to keep the EGR intact... JBrady had then mentioned to me that the EGR heat sensor has to be re-mounted onto the lower exhaust down pipe, and the mounting on the new header will not work (reads will be off or something to that effect) and if installed on the down pipe re-routing of some other crap will be necessary to make it all work..

The bottom line is that deletion of the EGR is only really necessary when installing aftermarket headers, and should probably remain intact otherwise. That is my take on it..... does that sound about right?

When deleting the EGR should that grime buildup on the intake be a concern after years of use?

 

[Toysrme]

Having the EGR -will keep the intake much cleaner

That part is backwards, but ya!

EGR has good & bad sides... But it needs to go if you're into performance. It creates problems.

 

[jtjerry]

heeh it is opposide effect jibby:
egr and its burned gases are making all that carbon mess in intake manifold.
I delete my egr 1 year ago.

car drive same with egr as without it. comsume same amount of fuel and perform same. There is only one better thing: egr will never give me ses code or stuck open. delete egr in 1uz it is 2 hours job and cost you less that 1 dollar for resistor for fool ecu.
there is my egr delete DIY in another forum:
if David want can copy it to lextreme as well
http://www.clublexus.com/forums/showthread.php?t=155439

thanks
Jerry

 

[cribbj]

Toysrme, I wasn't aware EGR provided any inherent enrichment, and I probably would have said the inverse was true. I would believe that the EMS in EGR equipped cars has to enrich the mixture when EGR is active, to mask the poor driveability it causes.

The legislation that required EGR was part of the Title 13 California Code 1968, which required all cars to be sold in California in 1988 and later years to have a diagnostic system (then called OBD1) and an emissions reduction system which specified EGR as one component. This requirement was relaxed somewhat in 1990, in preparation for the 2nd generation (OBDII) emissions requirements which were to be more performance based than the proscriptive OBD1. It also was aided when a coalition of foreign automakers, (with Toyota), demonstrated superior emissions reduction to the ARB, without the need for the unreliable and maintenance intensive EGR system.

At Cat & Cooper we took a close look at EGR in the 80's and both companies decided to follow the course set by the European carmakers with their advanced EMS's and high technology catalytic converters for our gas engines. EGR is really a solution of last resort for an engine developer, because it brings so many negatives and complications, for only one positive point - when it's working, it does work.

John

 

[jibby]

Got it guys, thanks!!..The EGR must go....


Thanks for the Link ...Jtjerry I remember posting on that...

 

[Toysrme]

Na it's cool. By displacing air (oxygen) content in the mixture. It is enriched.
For example purposes:
*The exhaust will contain little oxygen (Let's just say none).
*The fuel/air mixture would be 15:1

Say the EGR system is displacing 10% of the oxygen in that mixture, and the fuel stays a constant.
15*0.90 = 13.5.

The fuel mixture now, is effectively 13.5:1

 

[stevechumo]

I'm pretty much agreed with you guys from this point. Let's say if the piston rings got blown with the EGR there, what happens is the oil will find its way back to the intake. And now we can imagine how bad and dirty it is. As for the deleting of the throttle body coolant, I don't recommend it. It doesn't seem to have any side effect to performance or emission. It's more of benefitial for whomever lives in the cold states.

 

[jibby]

I just want to be clear on this one thing before we end this discussion ...

This question is directed for Zir, and jtjerry, who have both already blocked off their EGR's on your IUZ..'s for some time now.. Have you guys experienced any ill effects so to speak from blocking the ERG? Any pre-ignition or idle response problems?

For others, I am assuming by blocking the EGR you will have altered the A/F ratio at the higher rpm's?.. With the recycled exhaust/hot gases removed from the intake flow, I would assume the car will run richer at those higher rpm's. Does the ECU learn and adjust or do you always run rich? If what I am assuming is the case the car will run with less power if the mix is richer then being lean? So any HP's gained with the reduced heat intake due to EGR removal will most likely be void due to the richer fuel mix... Am I right or wrong on this?

 

[cribbj]

First clip is a quote taken from the "Report by the Committee on Motor Vehicle Inspections" 1973.

2nd clip is from the Toyota TIS

I really don't think EGR, in and of itself, does anything to enrich AFR. Since it's essentially an inert gas, it doesn't affect the O2 sensor feedback, and since it's injected "after" the MAF the engine fuel map doesn't know it's there. It does dilute the overall mixture that hits the combustion chamber.

Of course I could be wrong about this, and if so, I would be interested in seeing any reliable, independent references that prove otherwise.

John

 

[stevechumo]

John,
Do you remember that I sent you the attachment from Lexus manual of the EGR for the 1UZFE a long time ago? It pretty much explained everything. I lost it. So if you find it, could you send it to me?

As for the leaner or richer A/F caused by eliminating the EGR and not ideally Stoichiometric, I don't think we should worry about it. The O2 sensors will sense the difference and send the signal to the ECU to compensate for the new change. However, I'm not so sure if that resistor used to trick the ECU will affect the O2 sensors or not. The most simple way to know is installing the A/F gauge to the exhaust.

 

[Lambo]

Removal of hydro pump

Yep, those little circuits work great... I used one on the hydro pump plug and it tricked the ECU perfectly... Good pic's Zir......and deleting the EGR really does clean up the engine.. Man, I am going to have to remove my bling bling vacume lines:sorry:

Hi Jibby, Above you mention fitting a circuit to fool the hydro pump ecu, is it a transistor etc if so where do i find a circuit for one and what is involved
Regards
Lambo

 

[jtjerry]

I just want to be clear on this one thing before we end this discussion ...

This question is directed for Zir, and jtjerry, who have both already blocked off their EGR's on your IUZ..'s for some time now.. Have you guys experienced any ill effects so to speak from blocking the ERG? Any pre-ignition or idle response problems?

For others, I am assuming by blocking the EGR you will have altered the A/F ratio at the higher rpm's?.. With the recycled exhaust/hot gases removed from the intake flow, I would assume the car will run richer at those higher rpm's. Does the ECU learn and adjust or do you always run rich? If what I am assuming is the case the car will run with less power if the mix is richer then being lean? So any HP's gained with the reduced heat intake due to EGR removal will most likely be void due to the richer fuel mix... Am I right or wrong on this?

NO, there is no any issue about running car without egr for me. I drive my car dayly so I should easyli found any problems. Car start same, run same when cold, run same when hot, run same on light trottle, run same at WOT. simple: my car run as good with that egr as witout it. fuel economy is same too.
Jerry

 

[Lextreme II]

I have an EGR kit in my car for performance reasons. I also install a kit on Celsior God (Moderator from CL) completely stock LS400 and no ill effects what so ever. I did the EGR delete because my EGR pipe was cracked and I was having exhaust leak and my CEL came on. Secondly since i am running a turbo, this will reduce the lost of exhaust gas.

 

[MaxPower]

My 2 cents... The MAF measures the incomming stream and as said earlier the EGR is injected after it however the engine can only consume X amount of "air" At the intake valve the "air" will be made up of both fresh air and EGR air, the cyl will fill with the same volume of air as when the EGR is off except about 10% of it will be CO2, this means there should be a reduction in flow through the MAF while in EGR.

I also agree with toysrme's claim of a reduction in fuel by the ECU however i dont think the calculation is quite as clear cut as the small example above - during closed loop (when EGR is likely to happen) the AFR will never be at stoich (14.73:1), it jumps either side of this. The ECU determines the biasing for how long it stays rich/lean and the track rate so it is possible to be in closed loop with an average AFR of something other than stoich which would change the calculation somewhat due to the excess oxygen when leaner than stoich.


cribbj: Just speculating but the small clip you posted may be meaning that the AFR needed to be slightly richer than normal during EGR - ie at cruise they went for a target of 14:1 instead of 14.7:1 but to achieve this they may have had to full some fuel out still. In the Delco ECU code the on going fuel calculation has a few % multipliers, one of these is EGR dilution. The fuel correction can only be 0-100% reduction in the base injector pulse width, the calculation cannot add fuel at this point. If you want i can email you this part of the ECU code??

 

[jtjerry]

ya there should be reduction in flow through MAF but remember: mixture will have burned gases and it do not help with combustion.

Mixture of air+exhaust fumes+fuel will burn not as well as mixture of air+fuel, I think.

 

[cribbj]

MaxPower, I agree with your point on the EGR dilution multipliers as I'm familiar with them from other ECU's. I just don't believe that EGR "enriches" the mixture (unless the engine is already running so rich that it has loads of unburnt HC's in the exhaust)

According to some explanations, the EGR dilution multiplier is necessary because the engine will aspirate a few percent less air with EGR active, and thereby needs a few percent less fuel, so to stay at stoich, there needs to be a fractional dilution multiplier for the fuel map. But at the same time, EGR also introduces driveability problems, so to mask these, enrichment is also needed during EGR operation. Sounds to me like it makes for one very confused ECU......

Regardless of our different opinions on how it works, I think one point that we can all agree on is that EGR is a royal PITA for performance applications.

John

 

[jibby]

I am glad to hear everyone is happy with their EGR block and have had no reported problems too speak of...

I must say who would of thought to recycle already combusted exhaust back thru the engine to help with emmisions? I would have thought that there would be no O2 or any other reusable combustable materials left to send back thru the intake..I would have thought that idea to be rediculous...I would have thought wrong..Wow... Good for the masses, bad for us engine junkies..

Lambo- You asked where can I find the looping resistor? I am guessing any electronics store, or auto electric repair shop....that is where I am going to look for one..

 

[lorenzo816]

i pass emitions here in st. louis with no egr, not sure about the smog test you guys have in cali. I heard that the egr doesnt even do anything on idle so it might not even effect your emitions. (not 100% positive though)

Im sure youll figure out where to put the resistor, if you cant i can load a picture.

I passed the emmissions tailpipe test here with the CEL and a code 71 still on.
They don't plug in to the OBD on the older cars as mine is a 92.

So I think they rev the car and try to match some specific RPM and then get the sniffer to test - I passed a while ago... so I assume its cool

and later on.....

I just put the resistor in the plug the other day and have not got around to taking any of the egr unit off the car. So what's the harm for a little while? I'm getting good gas milage - and no CEL.
Wonder if I should just leave it this way - any thoughts?

--

Lorenzo 816
92 LS400
almost 200k!

 

[scotturnot]

Resistor location

I had my mechanic install the EGR Kit and I installed the S & S Headers. My harness has six wires on it (1995 Lexus SC400). Can you be more specific as to which wires need to be jumped in the harness. Maybe you can tell me what color the wires are? Maybe I am looking at the wrong plug. A picture would be great. Thank you in advance.

Did anyone anwser his question? Mine is a 97 and I also have six wires. Where does the resistor go?
Thanks,
Scott

 

[jibbby]

EGR kit? Need more information on this kit....I decided I want to try and keep my EGR intact with the S@S Headers...Need help on this one.....