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EGR delete or disabling through software

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

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  1. OptimusPriustus

    OptimusPriustus Active Member

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    After im+egr+cooler cleaning i am seeing lowest MPG’s ever. On a long road trip (80-100kmh) 56MPG. I think thats good given that car has 215kkm on the clock. Weather was some -2…+5, lower grill blocked and 15” winter tires with spikes. Probably i cannot reach same with 17” summer tires and grilles open

    p.s. here 98 is almost 10usd per gallon. So 56MPG is nice(y)
     
    #81 OptimusPriustus, Apr 13, 2022
    Last edited: Apr 13, 2022
  2. luis perez

    luis perez Junior Member

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    Good day!

    old post... let me try

    In an effort to troubleshoot my 2014 Prius C after reading several threads, I decided to simply wait until the engine started right: In the mornings most of the times it shivered, as I drove at 25-35Mph, etc. yesterday morning it did not so right there and then I disconnected the EGR drive motor, MIL ensued. Yes, now the car drives as it used to do 30K+ miles ago. I was confused thinking the car was leaking coolant somewhere, now I am finally certain it is not. A radiator fan failure that went unnoticed for at least a week is part of the event history. The MIL never lit up while the fan failed or the HVAC compressor failed to start. The car does not burn oil.

    I did catch a comment that once the ECU sees that there is "no EGR" then a "different map" is used, do you think that is the case? Would it be better to simply disconnect and let the system be "aware"?
     
  3. Paladain55

    Paladain55 Active Member

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    Disconnect is safe. I wouldn't do mechanical alterations outside of unplugging that electrical connector.
     
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  4. black_jmyntrn

    black_jmyntrn Senior Member

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    well,, heh.. something like that, just you need a special ECU programmer like the one I have. Mine isn't through OBD2 port either, the new one they say works is through OBD2 and I should have one in hand soon that way I can see if it works compared to the other methods I use now, just hadn't gone down the EGR route, mainly making changes to US Spec PIP to have similar parameters to the JAPAN spec. Hope is when I run an emissions test with this other app, the changes still allow to meet CA smog reqs with something extra in there... that and this M20A motor swap. :)

    also, I cant confirm hands-on yet, they say the new toyo/lex are encrypted and no canbus...
     
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  5. luis perez

    luis perez Junior Member

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    ".......outside of unplugging that electrical connector..."

    I am thinking that instead of simply leave something dangling, maybe simply find a separate motor & the connector, plug that motor to the ECU, the cut out connector to the installed EGR motor so noting can get to it's electrical port, and do not touch the original design. Every time you take apart something dirt will get in, no matter how careful you are.

    I think this would work for two reasons (reality check, any comments more than welcomed):

    a) The ECU wants to see a load saying "motor is here"
    b) When the ECU senses a plugged ECR the MIL light remains off. There is a chance that something will change to compensate and.

    Does anybody want to sell a just an EGR motor that can fit a C and it's associated harness connector? =)


    ...special ECU programmer...
    Although I know enough about electronics to work with digital and analog systems and follow electronic diagrams, troubleshoot, understand timing charts, a bit of assembly from the days of Motorola, etc. I rather focus my scarce energy on storing the values from the 2009 Prius odometer EEPROM. I will need to keep that car running for 500K miles =). I hope I can avoid winding up doing some type of special programming, if that happens, I would really appreciate your help. As of now, for the 2009 has a blinking fuel gauge. In the past I did replace the caps and it worked just fine. I am now looking for spare time to take apart the entire thing, while breaking a few vent grills, and check the wiring is properly seated as recommended by other posters. I do remember that when I was putting all that stuff together it was after midnight, so sure, I may have missed properly seating the connectors to the inclination & acceleration sensors. When I take out the odometer assembly to check connections I will backup the EEPROM =) & do the re-calibration procedure.......

    Just to confirm:
    It's now about one week after disconnecting the EGR motor. MPG went from 47 to 52.

    Yup... all of this is outside any practices recommended by Toyota
     
  6. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    See you when the head gasket lets go. ;)
     
  7. luis perez

    luis perez Junior Member

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    When that happens, I will let go of the car and send it to a junk yard, I will put and end to it lol.

    It is outside of my capabilities to be cleaning an EGR and intake manifold every 40K miles, or replace a radiator fan every 50K miles or so. I already received a letter from Toyota that I have until November to report a problem with the auxiliary brake pump (ABS) or it will not be replaced in the future. Of course the auxiliary break pump is going to give away, I have flushed the fluid and in a few months the color changed back to dark. I have already fixed that in the 2009. The C has only 47K miles.

    The cherry on the top: The beautiful blue paint is peeling off.

    At some point, yup, you have to let go =) It is just natural.
     
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  8. rjparker

    rjparker Tu Humilde Sirviente

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    You will still get a code and check engine when egr flow checking occurs.
     
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  9. DirkAshburn

    DirkAshburn Member

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    Does different gas affect the EGR assembly? Because I cleaned mine around 140k miles and it wasn't that clogged at all. I really don't get how people need to clean it so often, or how some are just totally clogged up as I've seen in some videos. Are you putting in the lowest tier gas you can buy?
     
  10. rjparker

    rjparker Tu Humilde Sirviente

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    It is bad when the low tension rings are burning oil and allowing excessive blowby. Gas has nothing to do with it. Some gas has better detergent additives for the injectors or back of the intake valves. No effect on exhaust hydrocarbons which end up in the egr cooler, the primary clog location. The egr valve and pipe don't get clogged.
     
  11. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    That sucks. Blizzard Pearl is known to peel, and blue too?
     
  12. Paladain55

    Paladain55 Active Member

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    Nah stick with making sure you get the check engine light by unplugging the connector. Some guy on here tried to mess with a valve similar to you and it didn't work. I plug mine in and out and it does fine. Doesn't really dangle or get dirty.
     
  13. luis perez

    luis perez Junior Member

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    At least mine is.... =)
     
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  14. luis perez

    luis perez Junior Member

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    Ok.... I had understood the computer did not care when the EGR system clogged somewhere, Ok, will cover both connectors and just let it be..


    A poster recommended a "P10 Premium Smart Vehicle Digital HUD Head Up Display OBD2 Car Speed Projector", did get one, for 34 it's a good deal. Among other items it shows Ox trim data in real time. You can set alarms for eng. temp, bat volt. and speed. I can say that B batt is off in the P10. Temp reading seem OK. I set the alarm at 94C. Thermostat should be wide open at 93C from what I can understand. The 2014 Prius C I have has a battery voltage that depends on whether you are parked or driving.

    FYI MPG is now hovering @ 53~55
     
  15. GregC1979

    GregC1979 Active Member

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    According to my gauge, under wide open throttle the most I've gotten it open is about 65%. At idle however, you are correct. But WOT it's open, believe me.
     
  16. GregC1979

    GregC1979 Active Member

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    They most certainly do have head gasket issues, just not on the scale of the Gen 3.
     
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  17. luis perez

    luis perez Junior Member

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    Hello! In eBay found a ECU for a 2014 P C, less than 15.00 including S&H. From what I can understand from a 2010 Repair manual, first you do a VIN re-learn then initialize the ECM by running the engine in monitor mode. Is that correct? My current ECM is fine, I simply would like to have a spare on hand.
     
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  18. Prius Enabler

    Prius Enabler New Member

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    All right experts.
    I am a Prius newb so be gentle. Had the beginnings of the hydro locking head gasket. Heads now rebuilt and sitting back on the block ready for reassembly.
    The reason I’m in this thread;
    Everything was packed with nasty black sludge! Intake ports, Injectors, valves, egr/cooler exit/piping and manifold plus manifold egr passages. Remember I’m a prius newb, I’ve never seen anything like this.
    Does the cooler create a condensation effect goobering all the particles into clumpulation? Mostly normal exhaust pipe look on the upstream end of cooler but downstream looked like one of those public bbq grates at the local park.

    What I have learned, egr is originally for emissions however the brains figured out it could be used to pressurize the manifold to lower pumping losses in closed/almost closed throttle positions.

    I do like this car but dismantling and cleaning the whole system twice a year is the stupidest bandaid for a terrible design I can think of.

    I ordered an air oil separator this morning for the pcv line like some have recommended, I’m thinking some of the buildup is from it burning the oil pool that I discovered below the throttle body.

    (Question) Has anyone come up with a solution that?
    1 Doesn’t turn on the cel
    2 Doesn’t affect pumping losses.
    3 Sends the crap to the cat instead of the egr.

    (Thought’s)
    1 Going through the trouble of moving egr tube downstream of cat - would likely be impossible to get the boys at the muffler shop to line up the new pipe with the cooler.

    2 What would happen if you capped the egr feed and had the egr somehow piped to filtered atmosphere? During pumping it would open and suck atmosphere keeping the manifold from going negative. Intake is closed so no fuel. I doubt at that low of throttle you would have lean issues. But would there be enough flow to keep the sensors happy?

    3 Turbo Atmosphere egr. I win the lottery and get a shop where I fab things eventually creating a tiny turbo to pressurize the manifold with clean pressurized Atmosphere.
    Perhaps called the Miller Cycle.

    4 Win another lottery and stop driving 150 miles a day in a Prius.

    5 I don’t care about emissions, the thing gets 50 mpg.
     
  19. rjparker

    rjparker Tu Humilde Sirviente

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    Blocking the egr does not require venting elsewhere; rerouting the pcv would need venting. No known way to disable the egr without recurring codes.

    At low rpm or wide open throttle the egr valve is closed by design.

    Eliminating oil burning will dramatically reduce carbon but requires new pistons, rings and valve seals. Easier to install a professionally rebuilt engine.
     
  20. Tombukt2

    Tombukt2 Senior Member

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    Generally EGR gas is reburned for emissions purpose to reburn the dirty nasty mess again and put as little out in the atmosphere as possible the way I understand it. The second thing EGR cools the internal combustion temperature of the running engine substantially so a motorized EGR valve that can be opened and closed by a computer at different times and different throttle positions would allow the engine or intake manifold to be flooded if you will with EGR gases to try and maintain the temperature we're talking about in the engines cylinder where the pistons going up and down and reburning this nasty junk essentially regurgitating its own puke the way a bird feeds young disgusting and you wonder why the engine internals are so dirty then this EGR gas that has to come from the pipe off of the exhaust manifold is sent through a cooler to cool it down I mean usually when you cool stuff like that down you wind up with black hard stuff or coking I think they call it in the metal business or gas business or whatever and this is what your essentially cleaning once it builds up look at that nasty mess so I'm not sure what they designed why and really don't care I know that this flood of EGR gas before the EGR valve that runs through those metal tubes in that cooler trying to cool it down turning it into diamond black material almost Little micro pellets of that crap getting pushed through these porch and your intake manifold and right back into your cylinder to supposedly get burnt up and pounded down again and then there's low tension rings on your Pistons because we can't have those holding the piston wall and doing their job properly we got to make that as weak as possible and we got these oil control rings that are about not worth it I don't know what All in the name of a few tenths of a mile per gallon I'll give up the few tenths and take what I had in my '06 to '09 without any of these troubles and close to 600k mi holy moly I've messed with this twice and it will not be happening again ever You get one chance and that's it I can't really say anything about the first generation 3 It was bought by my ex who's one of those it's red I want it she took it from 160 to 390,000 mi and it was never off the road she drove that car slap into the ground DoorDash Uber and nonsense so it didn't do too bad The only reason that is is because it stayed in the wind from 160 to 399 that woman didn't sit down practically barely slept through the whole pandemic so that did reasonably well but still and then if you saw the car it's completely trashed inside the tan interiors turned yellow and door panels are blowed out and it's just not. In the 13 Persona not even room for discussion it was just a horrid vehicle. Like the looks blah blah blah but I meant it I put my finger on the sheet metal I was like No I can't do this girlfriend wanted it I gave it to her been a yard ornament ever since.