Remove EGR

[timc]

Doing the HG on my 1997 LX450, and I do not want to reinstall the EGR, as it makes it difficult to get to the last intake bolts, and just in the way. I am going to have two cover plates made for the head and intake. Has anyone left theirs off? Does it throw any fault codes on the computer? Any other isuues with it off???

EDIT:
Also, Are their any other SMOG lines that I can remove on the 97? I have alot of vacum lines running around/under the intake that I'd also like to trash if I can.

I saw the SMOG thread, but that appears to be an earlier truck.
END EDIT.

We don't have emissions in SC so I don't have that issue to contend with.

Tim

 

[inkpot]

Howdy! MOST computers will throw a code if the EGR is not functioning properly. MOST modern vehicles run better with all the smog operating right. Potential buyers may live where they need smog testing. John

 

[mudking82]

Howdy! MOST computers will throw a code if the EGR is not functioning properly. MOST modern vehicles run better with all the smog operating right. Potential buyers may live where they need smog testing. John

X2. I think it would take some work to make the computer not throw a code, if it is even possible. You are OBD2. It will throw a code the first time you drive it. EGR is there for a reason. It helps your engine, reducing combustion temps to reduce pre-ignition/detonation which kills an engine. And if you go to sell it, or you move to another state that requires it, you will regret it then. I would leave it for sure.

Why do you want to remove other smog stuff? It is all there for a reason. It's not like it is going to give you gobs more HP/TQ or anything.

 

[94 Newbie]

Since your's is OBD II ...

I believe that yes, it will throw a code.

Not sure about the Toyota ECM , but in the GM Camaro world lots of people do this, and have the code tuned out !

See here for one example -

the whole search is here.

I can't speak for other states I/M inspections, but in Houston & surrounding smog counties vehicles w/ OBD II are only required to pass the "plug & play" test. What that means is that they hook the state computer to your vehicle - if the vehicle's computer reports no codes, and all is well, then you pass the emissions test.

My '94 is OBD I - I get to pass the sniffer test at 2 speeds - idle, and ~ 2100 RPM.

I get more work for the $ 39.95 I spend on inspections, but I also have to be within the legal parameters , too.

My Camaro SS ( '99 ) still has all the factory smog stuff on it - the only problem I have had w/ it is that one of the AIR pump checks went bad around ~ 55K. A $ 15.00 part resolved that issue.

I think if it was me, I'd find out first whether or not the ECM can be reprogrammed enough to remove the EGR inputs, and therefore any potential codes.

If it cannot, I'd leave well enough alone.

If you can live w/ the CEL in that scenario , at least keep all the EGR goodies in the garage for the next possible owner or for the time that you decide to add it back on to kill the light.



Good Luck !

Britt

 

[MikePL]

Your LX is OBD2 so removing the egr is not enough. You also need to buy a 1$ resistor and put it where the temp sensor goes to the intake (it's on the driver's side of the engine). There are a few threads about the procedure. Try searching 'resistor egr' or similar.

The temperature sensor is the only thing that controls the EGR functioning so if you put the resistor you can get rid of the EGR.

There is also a general opinion that the EGR system works only when idling or driving at a constant RPM for a long time. So basically it works very seldom and getting rid of the EGR will not increase temperatures, will not ruin your engine. There are many non-US 1FZ-FE engines without EGR and they are fine.

I have a faulty EGR system and instead of messing with it, I just put the resistor (a year ago). No problems at all.

Within 2 months (when spring comes) I will get rid of the EGR components.

 

[RavenTai]

EGR only operates at mid throttle, via my tests the peak being wile riding at steady speed slighlty dowhill

It does not oprate at all at idle or WOT,

The porpose of EGR is to add a inert filler (exhaust gasses) to the combustion chamber to keep the air temperature below 2500 degree's, at that temp nitrogen (78% of air) swaps from inert gas to an chemically active and can combine with oxygen to form NO or NO2

NO and NO2 are harmless by themselves but can combine with other stuff to form smog that can cause dificulty those with breathing problems.


on my FJ62 the lack of EGR has been no problem at all (at least for the motor, those with asthma may disagree) There have been many a 1FZ with a P0401 with no EGR flow and no engine problems either,

 

[OGBeno]

So, if removing the EGR is not really a difficult procedure and does not cause harm to an engine, how would one go about doing this procedure?

Besides the EGR valve, what else would go? EGR modulator, VSV and all associated bits under neath the intake plenum? What of all of the vacuum lines?

How, exactly, would one go about deleting these systems from the 1FZ? Would the ECM need to be reprogrammed to run the engine system without one?

More info. please.

Thanks.
-onur

 

[timc]

Your LX is OBD2 so removing the egr is not enough. You also need to buy a 1$ resistor and put it where the temp sensor goes to the intake (it's on the driver's side of the engine). There are a few threads about the procedure. Try searching 'resistor egr' or similar.

The temperature sensor is the only thing that controls the EGR functioning so if you put the resistor you can get rid of the EGR.

There is also a general opinion that the EGR system works only when idling or driving at a constant RPM for a long time. So basically it works very seldom and getting rid of the EGR will not increase temperatures, will not ruin your engine. There are many non-US 1FZ-FE engines without EGR and they are fine.

I have a faulty EGR system and instead of messing with it, I just put the resistor (a year ago). No problems at all.

Within 2 months (when spring comes) I will get rid of the EGR components.

Thanks Mike, that's exactly what I want to hear. Not looking for any performance gains, just a cleaner engine compartment and also just one less part to fail and throw a code. Along with the EGR valve, and the pipe that goes down to the head, what else can I remove? Where are you going to get the "covers" to bolt on to the intake and head when you remove the EGR?

Tim

 

[RavenTai]

How, exactly, would one go about deleting these systems from the 1FZ? Would the ECM need to be reprogrammed to run the engine system without one?

More info. please.

Thanks.
-onur

I have not nor do I plan to delete the EGR on my 80, there is just no good reason to do so, unlike the 3FE you cannot gain much working space by de-smoging a 1FZ,

But I do know the EGR system and hypothetically if I were to it would go something like this:

The temp sensor resistor is detailed in another thread, that tricks the ECU, that is the ECU's only window into EGR operation,

You could then unplug the two vacuum lines on top of the throttle body that go to the modulator, plug the ports on the TB and on the modulator. Depending on how discrete you are with you plugs and how good the inspector is it may or may not pass the visual portion of a smog inspection,

EGR is then disabled with the parts still in place, easily reinitiated

If you wanted to go further and remove the parts:

Unplug the VSV and cover and seal the plug to prevent corrosion of the pins or a short from water, possibly by packing the plug with dielectric grease then wrapping it in electrical tape and then heat shrink.

Remove the vsv and its bracket under the intake, plug the ambient line at the T with the purge valve, plug the bottom of the hard line that passes through the intake, cap the top of it also,

Remove the modulator and its bracket,

Remove the EGR valve and EGR pipe, source a cap for the EGR outlet on the head (good luck) use a new gasket as a template to fabricate a block off plate for the open port on the intake manifold, 5/16” 7075-T6 aluminum worked well for the 3FE, install both.

You could possibly also do something with the charcoal canister and its purge valve, you would get a fuel smell and also possibly a fire hazard, if you have a 93/94 there is the pair valve and associated duct work,

That about all a 1FZ can do without, really not much change in access especially on the later motors,

 

[OGBeno]

I have not nor do I plan to delete the EGR on my 80, there is just no good reason to do so, unlike the 3FE you cannot gain much working space by de-smoging a 1FZ,

But I do know the EGR system and hypothetically if I were to it would go something like this:

The temp sensor resistor is detailed in another thread, that tricks the ECU, that is the ECU's only window into EGR operation,

You could then unplug the two vacuum lines on top of the throttle body that go to the modulator, plug the ports on the TB and on the modulator. Depending on how discrete you are with you plugs and how good the inspector is it may or may not pass the visual portion of a smog inspection,

EGR is then disabled with the parts still in place, easily reinitiated

If you wanted to go further and remove the parts:

Unplug the VSV and cover and seal the plug to prevent corrosion of the pins or a short from water, possibly by packing the plug with dielectric grease then wrapping it in electrical tape and then heat shrink.

Remove the vsv and its bracket under the intake, plug the ambient line at the T with the purge valve, plug the bottom of the hard line that passes through the intake, cap the top of it also,

Remove the modulator and its bracket,

Remove the EGR valve and EGR pipe, source a cap for the EGR outlet on the head (good luck) use a new gasket as a template to fabricate a block off plate for the open port on the intake manifold, 5/16” 7075-T6 aluminum worked well for the 3FE, install both.

You could possibly also do something with the charcoal canister and its purge valve, you would get a fuel smell and also possibly a fire hazard, if you have a 93/94 there is the pair valve and associated duct work,

That about all a 1FZ can do without, really not much change in access especially on the later motors,

Interesting RT....I am not planning on doing this either, but nonetheless it is interesting to think about how this might be done.

Regarding the EVAP/charcoal canister. If it was deleted from the system, couldn't you just reroute the line the comes from the gas tank and send it right to the VSV underneath the intake plenum?

To a certain degree, the fuel vapor buildup in the charcoal canister is used in the combustion process anyway--instead of sending it through the canister you could just send the line from the tank right to the combustion process.....

At least, it makes sense to me....

Thanks for the explanation.
-o-

 

[RavenTai]

Regarding the EVAP/charcoal canister. If it was deleted from the system, couldn't you just reroute the line the comes from the gas tank and send it right to the VSV underneath the intake plenum?

To a certain degree, the fuel vapor buildup in the charcoal canister is used in the combustion process anyway--instead of sending it through the canister you could just send the line from the tank right to the combustion process.....

At least, it makes sense to me....

Thanks for the explanation.
-o-

There was a past thread where the vent line in the bottom of a charcoal canister became clogged with mud, instead of the intake vacuum drawing fresh air from the vent line through the canister it instead evacuated the fuel tank collapsing it, the guy went through 2 or three fuel tanks before he figured it out,

doing as you say would do the same thing, the tank needs an atmospheric vent somewhere, right now it is through the charcoal canister,

 

[OGBeno]

There was a past thread where the vent line in the bottom of a charcoal canister became clogged with mud, instead of the intake vacuum drawing fresh air from the vent line through the canister it instead evacuated the fuel tank collapsing it, the guy went through 2 or three fuel tanks before he figured it out,

doing as you say would do the same thing, the tank needs an atmospheric vent somewhere, right now it is through the charcoal canister,

Couldn't the pressure differential be mitigated with a vented gas cap?

Or, just a T-ed line from the gas line hose that is rerouted to the VSV that is then vented?

There's gotta be someway to get rid of the canister and still allow for pressure differential in the tank....

 

[RavenTai]

Couldn't the pressure differential be mitigated with a vented gas cap?

The stock cap has a check valve that lets air in as fuel is removed but the flow rate is too small to keep up with the purge valve,

Or, just a T-ed line from the gas line hose that is rerouted to the VSV that is then vented?

Vapors mainly come out of the fuel tank when the engien is off, so basically all you have done is make a vacuum leak and still have the smell and fire hazard problems Might as well just cap off the purge valve and vent the tank to atmosphere as that is what you are doing,

There's gotta be someway to get rid of the canister and still allow for pressure differential in the tank....

Certainly there is, I am just saying that hooking it up to the purge valve is not the way,

one possibility might be to hook the tank to the ambient line where the EGR VSV used to hook in, the vapors would fill the upper intake (pre throttle body) and then the air filter canister and would only escape after those spaces were filled, unfortunatly if the vapors did "overflow" they would end up in the right fender where they coudl get sucked into the cabin fan intake

if you ever had a backfire on start there could be an explosion if the mixture was right destroying all kinds of expensive parts,

probably the best way to vent a tank is through a charcoal canister.