EGR delete or disabling through software

Discussion in 'Gen 3 Prius Main Forum' started by Juntuner, Apr 30, 2021.

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  1. Juntuner

    Juntuner Junior Member

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    Hello

    I have disabled my EGR system by removing the magnet in the Egr Valve that operates the worm wheel mechanism .

    I did this as my car was shaking at certain load conditions (going up inclines)at 55 to 65 mph

    The shaking issue is now Gone and the car drives smoothly and like new

    I want to disable my EGR system as we dont have an EPA where I am and my car runs much better and uses less fuel as a result of doing so and also know the engine will last much longer as a result .

    I have a few questions about the EGR SYSTEM

    1.Can I disable or greatly reduce the EGR duty cycle using techstram or any other software without getting a check engine light ?

    2.has anyone successfully re-routed the EGR gases coming from the eEGR valve so rather than going into the intake manifold they are redirected back into the exhaust or elsewhere ?
     
  2. rjparker

    rjparker Senior Member

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    My understanding is there are no techstream adjustments for the egr other than testing it. Others may know otherwise. I don't think an egr reroute is necessary from an exhaust gas flow standpoint as it is routinely off/closed anyway in normal operation like idle and low load situations. It is possible that yours was stuck open to a degree impacting fuel trims.
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe yes; maybe no?
     
  4. ChapmanF

    ChapmanF Senior Member

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    Regarding the second point, how long the engine will last, you should probably know it is widely believed on PriusChat that to do as you have done will lead to a head gasket replacement in short order. I'm not fully persuaded on all the points of that argument myself, but you'll probably want to at least get familiar with the posts of some of the strong believers of that idea.

    When the ECM knows the EGR is malfunctioning, it will run the engine with protective fallback parameters trying to avoid damage. If you simply unplugged the valve, the ECM could log P0403 immediately and would run the engine protectively, but with your chosen mod, removing the rotor, you'll prevent the ECM detecting the P0403 condition, and it won't take any steps to protect the engine until it detects P0401, which could take a while.

    Regarding using less fuel, one of the purposes of EGR in a spark-ignited gasoline engine (the kind the Prius uses) is to improve fuel economy (that stands in contrast to diesels, where it only helps emissions but hurts fuel economy). So if you are seeing fuel economy improvement with your mod, there is more to the story than your post contains.
     
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  5. AzusaPrius

    AzusaPrius Active Member

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    The EGR system is already designed to reroute the exhaust gases.

    This is what helps save fuel.
    Friction and fuel burning is what heats up the engine block.

    The coolant and oil are what keep the engine cool.

    The purpose of the EGR is to recirculate the exhaust and maintain the engine temp.

    Saving fuel since the engine does not have to inject more fuel to do so.

    Removing the EGR would only waste more fuel and not save fuel.

    I would clean the EGR out and put it back.

    http://www.RedBullet.net

    http://www.ProjectLithium.com

    http://www.Pulstar.com

    http://www.PlugOutPower.com
     
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  6. Juntuner

    Juntuner Junior Member

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    I fitted a new EGR and it was still shaking .thanks for your input about tech stream
    disabling the egr by removing the magnet makes a massive difference to the way the car drives
    just dont take it out -do 100 miles -and put it back in
    as the car was Having crazy preignition and was knocking like crazy and you could feel the ecu retarding the ignition timing

    EGRs are a way of cheating the emission as far as I am concerned and contaminate the engines ,the oil, gum up rings and cause many other harmful situations .
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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  8. Grit

    Grit Senior Member

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    I would pay to see this work!!!
     
  9. frodoz737

    frodoz737 Top Wrench

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    Mixing raw exhaust with a filtered clean air/fuel mix in is not good for any engine. The sole purpose of the EGR system is to help reduce smog...period. Any warm up benefit is marginal at best.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    The EGR isn't there for any warmup benefit. Whoever brings that in is mixing up the EGR with the exhaust heat recirculation system (EHRS). They're totally separate systems.

    [​IMG]

    The EGR is there both to reduce NOx emissions and to improve fuel economy, just as in other spark-ignited gasoline-engine cars. The fuel economy benefit isn't peanuts, either.
     
  11. Juntuner

    Juntuner Junior Member

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    I believe the EGR is what causes the headgasket to fail on the gen3 prius .

    my belief and theory is :-

    The re directing exhaust gases and contaminants i.e black soot particles from the EGR upon entering the combustion chamber under compression become like glowing hot embers and cause pre ignition and that causes the head gasket to blow over time !

    watch this at 2mins 20 for my proof ( I dont like to put theories out there without proof)


    The fuel economy has definitely improved
    All the ECu is trying to do is compensate
    The ecu can only do so much at the end of the day the spent exhaust gases entering the egr cooler is somewhere around scorching hot at around 1200c and post egr cooler It would be interesting to see how effective that small water fed EGR cooler is at reducing the 1200c exhaust gases TEMP.

    I believe my MPG has improved during my EGR disabling experiments as

    1.hot air temps kill MPG as the air is less dense with oxygen when its hot ,this is why turbo cars have intercoolers
    2.Exhaust gases pollute the fresh air coming from the air filter which kills MPG
    3.The Carbon embers entering the engine cause knock and then the ECU Detects knock this at it retatds the ignition timing which Kills MPG

    I would like to see the knock count with the egr enabled and disabled to verify this as its a theory?
    I would like to test the EGR temps post and After the EGR COOLER
    I Would also like to see the the IAT intake air temps at the intake manifold with and with the egr connected

    I have tried the method I mentioned above and 100% the car driver better its silky smooth ,and its also faster and better on fuel according to the gauges in the vehicle


    by the way the egr is not there to lower mpg as you say its designed to lower the effective emissions No2 especially by partially recirculating the gases twice
     
    #11 Juntuner, Apr 30, 2021
    Last edited: Apr 30, 2021
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  12. ChapmanF

    ChapmanF Senior Member

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    That puts you in direct contradiction of the folks on PriusChat who believe that clogging of the EGR is what causes the headgasket to fail. That's not necessarily a bad thing; we might learn a lot from how you and they work through that contradiction. I'll be watching with interest.

    I'm not sure who said that. On diesels it does (or at least used to) lower MPG. On SI gasoline engines it raises MPG (while also reducing NOx emission). The benefit to MPG can be on the order of 18% per this source (for "high-pressure cooled EGR", which is what we've got; "low-pressure" would be taking the exhaust downstream of a turbo), or "between 5 and 30 per cent" per this source, "with the largest improvement occurring in the typical enrichment region." So again, not exactly peanuts.
     
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  13. rjparker

    rjparker Senior Member

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    And the Beat Goes On. Back to the head gasket root cause. Early music video (pre Cher plastic surgery) ... advanced control was "electrically they keep a baseball score" while "the cars keep a going faster all the time."

    I like the preignition theory combined with excessive oil consumption, thermal cycling, poor head to block ports and the inclusion of a poor egr design.



    The primary function of an egr is to add exhaust gases to combustion to reduce combustion temperatures which reduces the formation of pollutants.

    However the egr is off at idle and wide open throttle. It does function at part load and effectively reduces the engine size (less fuel air) to allow efficiency and cleaner operation, which is what Toyota was going for on gen3 and reliably achieved on gen4.
     
    #13 rjparker, Apr 30, 2021
    Last edited: Apr 30, 2021
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  14. AzusaPrius

    AzusaPrius Active Member

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  15. Grit

    Grit Senior Member

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    thats insanity! a pc user here claims.
     
  16. ChapmanF

    ChapmanF Senior Member

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    First, if you're going to argue with something I said, get what I said right.

    Did I say it's not there for warm up time? Yes I did. You're right about that part. I said EHRS is a separate system (and it is).

    Did I say it's not there for saving fuel? No I didn't. I've clearly said it is there for saving fuel, even providing sourced references for the fuel it saves. Did somebody else say it wasn't for saving fuel? Fine, 'argue' that part with them.

    The EGR doesn't have a 'sole' purpose, it has a 'dual' purpose. In a spark-ignited gasoline engine, it (1) reduces NOx emissions (by a huge amount), and (2) saves fuel.

    The EHRS pipes engine coolant through a heat exchanger built into the exhaust pipe, controlled by a wax thermostat opening and closing a valve, as shown in the diagram above and the one below.

    If you're prepared to 'argue' how the EGR is somehow necessary for that to work, here's your chance.

    [​IMG]
     
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  17. wheezyglider

    wheezyglider Active Member

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    That very much sounds like the EGR passages in the intake manifold need cleaning. They are proven to clog unevenly, which leads to misfires during active EGR operation. It's not a difficult task but it's easy to miss the small inlets to go to each cylinder port. (Of course, with the valve defeated that's no longer necessary.)
     
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  18. AzusaPrius

    AzusaPrius Active Member

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  19. PriusCamper

    PriusCamper Senior Member

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    Sounds to me like you're about due for a blown headgasket and scapegoating the EGR system as the source of the problem won't mean very much anymore once you're debating on replacing whole engine with low mileage one or just doing the head gasket.
     
  20. ChapmanF

    ChapmanF Senior Member

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    Let's compare that to what I actually said.

    As you can see, I said it isn't there for any warmup benefit; there's a whole other system that's there for that purpose.

    I did not take any position on whether the EGR ends up affecting warm-up time in any way. I don't know the answer to that, any more than you do. It may or may not have some incidental measurable effect; that's just simply not why it's there.

    That brings us to you saying this:

    Which is just simply false. The EGR is there for two purposes, widely covered in open literature, neither one of the two is what you're saying its 'sole' purpose is, and the idea that the separate EHRS system somehow depends on it is plain bonkers.
     
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