1. Attachments are working again! Check out this thread for more details and to report any other bugs.

"EGR DELETE" Instructions

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Paladain55, Jun 17, 2023.

  1. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,675
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    He does say something like I "go up one side and down the other" of @NutzAboutBolts , regarding his EGR video. I hope I don't come across like that; that'd be like tugging Superman's cape, stepping on you-know-who's blue suede shoes. The @NutzAboutBolts guys are a godsend. (y)
     
    bisco likes this.
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,050
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    most of his comments are tongue-in-cheek i think.

    "this isn't your latest colonoscopy"

    "margie, put that on ebay for 3 cents"

    what a great voice too, made for documentary narration
     
    Mendel Leisk and JohnPrius3005 like this.
  3. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    8,493
    5,056
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    I would do an egr delete if it did not bring up a check engine. Which then partially masks off other issues. Maybe if someone programmed a $30 P10 scanner to monitor (which it can) and then delete that code while it displays coolant temps...

    Prius P10 Scanner.jpeg

    PS: Priuschat has become the modern way for old men to sit around the neighborhood Diner telling each other stories...
     
    #23 rjparker, Aug 10, 2023
    Last edited: Aug 10, 2023
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,050
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    yep, i resemble that remark :). but disagree with 'has become'. seems like it's been this way for the last 18 years, at least.
    chat is chat
     
    m.wynn likes this.
  5. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Delete the P0403, though, and you're inviting detonation and consequent engine damage, for as long as it takes for the code to be detected again. The code is what reminds the ECM "right, no EGR, go easy on the timing."

    As a practical matter, though, because P0403 is detected by a pure judgment of electrical continuity through the valve motor, it takes not long at all to detect, and a scanner trying to keep it deleted would be busy all the time.
     
    JohnPrius3005 likes this.
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,050
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    so if i disconnect the power, the engine light should come on and the car shound operate properly again if the problem is egr/manifold related?

    and when i reconnect the power for inspection, the light should go away?
     
  7. shmu

    shmu Junior Member

    Joined:
    Dec 19, 2016
    14
    11
    0
    Location:
    cincinnati
    Vehicle:
    2011 Prius
    Model:
    III
    I have a 2011 Prius with 89k miles on it. The obd app shows a good egr flow at around 20kPa consistently.

    I tried the egr delete and following is my observations:

    Before egr delete I drove 13 miles of highway and streets and had a mpg of 57.
    Then I did the egr delete. It showed the check engine light and my obd scanner iphone app showed the code P0403.
    After egr delete I drove another 13 miles on the same route and got a mpg of 58.
    The driving experience did not feel any different.

    I feel the egr delete would be a great option for my prius since the egr flow is still good and I can stop the egr clogging progressing any further.

    Please advice on the implications for following plan:
    1. Keep the prius in egr delete.
    2. Since the engine light is always on, Check the obd codes, every time at gas fill up to make sure there are no other engine codes.
     
    Bill Norton and TheMainePrius like this.
  8. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,675
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I’ll just cut to my bottom line: EGR clean.
     
    m.wynn and tankyuong like this.
  9. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    8,493
    5,056
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Come on, he is right except the egr flow will go bad when it does a periodic test. Still I would not want a check engine light up all the time when a five minute overheat could kill the engine. People respond to a check engine light better than one of the others they never see or read about.
     
    Mendel Leisk likes this.
  10. Paladain55

    Paladain55 Active Member

    Joined:
    Oct 20, 2021
    383
    147
    0
    Location:
    The South
    Vehicle:
    2010 Prius
    Model:
    Two
    I agree. I did a hero run like 40 miles one way and 40 miles back and with and without the egr delete when it was 70s and dark out. EGR run got 65mpg, egr delete run got 67mpg. So not statistically significant, but it doesn't seem to hurt.

    I just run around with a scan gauge plugged in 24/7 as i love to see my per trip avg, and i can scan my codes at any moment.

    But yeah the egr delete is pretty great. So if you do the egr delete, it will set the code, and if you plug it back in it knows the egr valve is functioning correctly again, but you will have to use an obd2 code reader like the scan gauge to clear the code. Then you can just drive around until the obd2 cycle completes again and says ready. Then you can go do an emissions test or whatever you need to do, and unplug it again in wait for the next one.

    I'm not gonna lie seeing the cel light bugs me a bit, but my car is just as reliable as my friends absolutely bulletproof 2005 toyota corolla 5 speed manual. Car has a maxxed out odometer, and has never need anything except a clutch, a 12v battery, oil changes, brakes, serpentine belts etc...

    At this point since the prius has no accessory drive and if you use the regen brakes correclty. My car never needs brakes, accessory drive, alternators, etc...

    Just oil changes, brake lubes, tires, and fluids. The prius is my favorite car now. Hilarious considering as a kid i was a big car guy like my dad and hated priuses and their drivers. Thought those people just hated driving. Wrong. Its just a fantastic tool, kinda like an indestructible Speed Queen washer and dryer set.

    I agree though. Keep the EGR clean or delete it. If you don't do one of these things, you will blow up! So be careful.

    Also p0403 sets so quickly its never going to be possible to clear it out as you drive. At this point the EGR delete that I know of has probably helped like 3-4 dozen prius owners that i know of avoid head gasket failure. Whether they deleted it until they had time to clean the system, or if they left it deleted. Some people can't afford to get the EGR done without the know how to do it themselves and lack of cash to get it done. So whatever works for you.
     
    Bill Norton and bisco like this.
  11. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,050
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i traded it in. solved a lot of gen 3 problems in one quick stroke :cool:
     
    #31 bisco, Nov 12, 2023
    Last edited: Nov 12, 2023
  12. Paladain55

    Paladain55 Active Member

    Joined:
    Oct 20, 2021
    383
    147
    0
    Location:
    The South
    Vehicle:
    2010 Prius
    Model:
    Two
    don't worry the new owner will probably find their way here
     
    TheMainePrius and bisco like this.
  13. Paladain55

    Paladain55 Active Member

    Joined:
    Oct 20, 2021
    383
    147
    0
    Location:
    The South
    Vehicle:
    2010 Prius
    Model:
    Two
    duplicate
     
    #32 Paladain55, Nov 12, 2023
    Last edited: Nov 12, 2023
  14. Dr_Marcos

    Dr_Marcos New Member

    Joined:
    Sep 21, 2024
    1
    3
    0
    Location:
    California
    Vehicle:
    2014 Prius v wagon
    Model:
    Four
    The relation of clogged EGR with HG issues makes sense because back in my country (Brazil) the G3 Prius doesn't come with EGR and there's no HG issues AT ALL. I mean nobody ever had any HG issues like we have here in USA.

    I'm on my 3rd G3 Prius that is actually a '14 V and I'm sick and tired of clean EGR's each 20k miles so I will stick to the EGR unplug and give that theory a shot.
     
    Bill Norton, bisco and Merkey like this.
  15. StarCaller

    StarCaller Senior Member

    Joined:
    Feb 15, 2014
    1,256
    706
    0
    Location:
    Cedar Crest, NM, USA
    Vehicle:
    2014 Prius
    Model:
    Two
    Welcome to the club / ;)
     
  16. MPGS-LOL

    MPGS-LOL Junior Member

    Joined:
    Jun 6, 2011
    19
    9
    0
    Location:
    Somewhere sperical, with lots of v8's
    Vehicle:
    Other Hybrid
    Model:
    V
    Rediscovered this thread recently.
    Are those who have lived with the CEL and unplugged the EGR connector still happy with their decision in the past year?

    If living with the dummy light is the only downside, I'll join the ranks of EGR Delete.
     
    Bill Norton likes this.
  17. StarCaller

    StarCaller Senior Member

    Joined:
    Feb 15, 2014
    1,256
    706
    0
    Location:
    Cedar Crest, NM, USA
    Vehicle:
    2014 Prius
    Model:
    Two
    car just runs like before /
     
  18. MAX2

    MAX2 Member

    Joined:
    Aug 12, 2024
    371
    88
    10
    Location:
    Third Rock from the Sun
    Vehicle:
    2007 Prius
    Model:
    N/A
    You can always check and indicate the fuel consumption value with the EGR on, as well as the fuel consumption value with the EGR off and the engine check light on. This is some kind of objectivity.
     
  19. Paladain55

    Paladain55 Active Member

    Joined:
    Oct 20, 2021
    383
    147
    0
    Location:
    The South
    Vehicle:
    2010 Prius
    Model:
    Two
    Exactly the same. No change in mpg. Only difference i notice is it has slightly more acceleration down low because it has less egr filling the intake. I run around with a scan gauge anyways so i can always check.

    Not entirely sure but i imagine its year 3 now. 3 years ago i thought the car was gonna blow up.
     
  20. MChris752

    MChris752 Junior Member

    Joined:
    Apr 8, 2022
    8
    4
    0
    Location:
    Phoenix, AZ
    Vehicle:
    2011 Prius
    Model:
    Two
    Had some hesitation, felt like almost stalling. Manifold ports of course clogged so i cleaned that all out, fixed the problem. Don't really wanna deal with it getting clogged again. Decided to unplug my egr sensor, car still runs like a champ. Feels a tad smoother actually.
     
    Bill Norton likes this.
  21. MAX2

    MAX2 Member

    Joined:
    Aug 12, 2024
    371
    88
    10
    Location:
    Third Rock from the Sun
    Vehicle:
    2007 Prius
    Model:
    N/A
    Have you disconnected the EGR sensor?
    But where is it located?
    Perhaps you are confused about something.