Still have P219A - Rough at Cruise Speeds - Cleaned IM Already

Discussion in 'Gen 3 Prius Technical Discussion' started by Preston Shobe, Jan 8, 2019.

  1. Preston Shobe

    Preston Shobe Junior Member

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    The car runs rough (misfiring) if I'm cruising easy at 65mph and below on flat terrain. As soon as I climb a hill and undergo a load, the car runs as smooth as ever. If I speed up to 70-80mph, its also smooth even on flat terrain (assuming this is because I'm at higher rpms). If I'm on flat terrain at 60mph with the cruise set and its running rough, all I have to do is cancel cruise causing the car to go into idle, and it also runs extremely smooth then.

    - So far I've pulled the intake manifold, cleaned it and the EGR pipe (but not the cooler).
    - I've changed all four spark plugs, and the driver side plug was shot and undoubtedly not working.
    - I just checked all coil packs and they're all working.
    - Changed the PCV Valve

    P219a says something about air to fuel ratio being off, so could it be a maf sensor or o2 sensor? Or could I really be in trouble and have a bad head gasket? I'm starting to really want to bang my head against a wall! Thanks in advance!
     
  2. Raytheeagle

    Raytheeagle Senior Member

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    How did you pull the codes, or what device did you use?

    Is that the only code?

    How many miles on your Prius?
     
  3. Mendel Leisk

    Mendel Leisk Sidewalk Supervisor

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    How was the pipe, how clogged?

    I'd second the miles question, it's pretty much the yardstick for egr build-up.
     
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  4. JC91006

    JC91006 Senior Member

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    Did you replace the intake manifold gasket? Sounds like bad A/F mixture
     
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  5. Preston Shobe

    Preston Shobe Junior Member

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    So far yes, its my only code via free code reading at a local auto parts store. I also have a cheapo bluetooth code reader and it only pulled the one code as well, so maybe a real code reader could find more codes..

    Car as 149,000 miles. Forgot that detail.
     
  6. Preston Shobe

    Preston Shobe Junior Member

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    I did replace the gasket, yes. Bad A/F mixture is what the code says it is, but I'm just not sure why. I have spark, so I'm wondering if it could be an injector or a maf or o2 sensor.
     
  7. Preston Shobe

    Preston Shobe Junior Member

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    In my opinion it had a fair amount of build up, but I've never seen another to compare it too. It wasn't plugged though. Car gas 149k miles.
     
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  8. ASRDogman

    ASRDogman Active Member

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    The cooler is what clogs. You only did part of the job.
    The pipe can be clean, but if the cooler is clogged it won't matter. You were so close, why didn't you complete the job?
    NOT MAD! Just wondering....

    It would be like changing 3 of the 4 spark plugs that are all broken, the engine won't run correctly.
     
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  9. Preston Shobe

    Preston Shobe Junior Member

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    I guess because every post and video I saw pertaining to p219a, lead to guys cleaning just the intake manifold and egr pipe and that solved their issue. Plus another post I saw talked about how much more of a job it is to do the egr cooler, so I figured if the majority are getting away without cleaning it then I might too. Took the lazy route :unsure:
     
  10. Mendel Leisk

    Mendel Leisk Sidewalk Supervisor

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    Cleaning the pipe is easy, and good to do first, because it gives an idea what the rest is gonna be like.

    Cleaning the rest I would budget a weekend of down time, especially the first go 'round. The wipers, wiper motor, windshield cowl, all need to come off.

    Coolant lines need to be disconnected. I found preemptively draining a couple of quarts of coolant into a clean container a good ploy, then the EGR system is completely above the coolant left in the system. Just pour it back into reservoir when everything's reassembled.

    The EGR valve/cooler assembly doesn't surrender easy: there's about half a dozen connection points, the aforementioned pipe needs to come off, connection to the exhaust manifold (watch you don't drop the gasket at that connection).

    There's one nut on a stud at the underside of the cooler that's nigh impossible to reach. It is possible, but there's so much in the way, it's blind. One consolation: the stud can be left on. If everything else is disconnected first, the nut removed from the underside stud, then the assembly can be lifted off. And consolation number two: leaving that nut off at reassembly, the whole thing is still very sold, makes it easier if you ever revisit.

    There are other studs that do need removal, for those you need an E8 Torx socket. If you ever want to remove the studs on the intake manifold (throttle body hold-down) an E6 socket is needed.

    Again, the removal and install can be done in 5~6 hours, but considering head scratching, screw ups, and protracted cleaning of the cooler/valve, budget a weekend.
     
    #10 Mendel Leisk, Jan 9, 2019
    Last edited: Jan 9, 2019
  11. JC91006

    JC91006 Senior Member

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    I got to the "impossible" nut by using a short extension and a socket, slip it in from the side. Comes out nicely. Can't use a wrench (no torque possible with the little wiggle space)
     
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  12. litesong

    litesong Member

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    Try some 100% gasoline without ethanol(E0). Sometimes that smooths out some roughness. Closest to Lima, Ohio is:
    Casey's General Store
    100 S Dixie Hwy, Cridersville, OH; 419-645-4455; ethanol-free CASEY'S 91(octane?)
    Probably won't need 91 octane. Check pure-gas.org for stations with 87 octane E0 in the region.
    Ohio has little 87 octane E0, however. Curtice has some 89 octane E0.
     
    #12 litesong, Jan 9, 2019
    Last edited: Jan 9, 2019
  13. The Critic

    The Critic Resident Critic

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    Do a leakdown test and report back with your findings.

    Some of the non-atkinson cycle versions of the 1.8L had issues with the cylinder head. More info on this here:
    Download Rate Exceeded
     
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  14. ASRDogman

    ASRDogman Active Member

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    I can understand that. :)
    But it's not near as hard as some people are making it. It's very easy to remove the wiper assembly. Only takes about 10 minutes?
    Removing all the nuts and bolt was also easy. Just take your time. And depending on the tools you have it goes quickly.
    A 1/4(snap-on) swivel helps for those hard to get at nuts, bolts, and studs. I have a 2010 and everything came right out.
    This was a job I've never done, and by watching the videos, and making adjustments, I had everything apart, cleaned,
    and back together in about 4 hours.
    Just make sure you have all the gaskets! I had to wait a day for the intake manifold gasket. I didn't think I needed it,
    but the original one was squished and it would have leaked.
    Draining some of the coolant would help, but I only lost about a cup of coolant so it's wasn't that big of a deal.
    At least the only thing you need to clean is the cooler! :) :)
     
  15. Preston Shobe

    Preston Shobe Junior Member

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    Haha that is true - just one last thing to clean lol. I'm familiar with pulling the wiper assembly out because I had to do that to change the plugs lol..again it sounds like I had most of the stuff apart to just remove the cooler :confused: At least I know how to get it apart which should speed up the process when I tackle it again. Its getting cold here in Ohio (and even colder (-1) this weekend!!). One thing is for sure, it runs just fine when its cold. Once its up to temp is when it for sure acts up, so living in town and making short drives running around town, I haven't really noticed the shuddering lately. Wonder why the temperature of the engine has an effect on whats happening? Anyway, EGR cooler is next so I'll keep you posted when I do it. Might take it up to my parents house where the have a brand new fully insulated garage with a *heater* :)
     
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  16. ETC(SS)

    ETC(SS) The other One Percenter.....

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    I only had time to skim, but I'd take another look at the MAFS first, just because it's so easy to rule out....then the EGR cooler...
     
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  17. ASRDogman

    ASRDogman Active Member

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    Garage is NICE! :) Sounds like some a sensor is bad. Not sure what the Prius uses, but Mercades had a cold start/enrichment valve that acted the same way when it was bad. It always thought the engine was cold even when it was hot. The Temp sensor could be bad also. Or as ETC said, the MAFS could be bad. All things to check before you get somewhere warm to do the cooler.
     
  18. Preston Shobe

    Preston Shobe Junior Member

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    Should I test via multimeter or buy a new one throw it in and see if it works. They are pricey little things!
     
  19. Preston Shobe

    Preston Shobe Junior Member

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    If I removed the pipe between the intake manifold and the EGR cooler and drove the car, if it drove fine would it imply its an EGR cooler issue, or is that not a valid test? I've got it in the garage and getting read to tear into it again!
     
  20. Preston Shobe

    Preston Shobe Junior Member

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    Ah hah!! Pulled the plug on the EGR valve and the problem went away. I hate EGR. Anyway, I may just run it this way for a bit and then come spring I may buy a new valve and clean the cooler. Car runs so so much better now!
     
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