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Rebuild Engine/Cat or Replace the Whole Car?

Discussion in 'Gen 3 Prius Main Forum' started by theheapstoe, Dec 12, 2022.

  1. theheapstoe

    theheapstoe Junior Member

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    Hey guys, I live in CA and got the dreaded P0420 code. My car is 12 years old at this point and although I love it, I'm in a bit of a pickle with what to do next. It's at 146,000 miles, no rust damage on the body, no major damage.

    So I have two options:

    1) Replace the engine and catalytic converter for 6k and hope it gives me another 100,000 miles without anything vital breaking down.

    - OR -

    2) Sell the car for what I can and buy a newer Prius (or any car) for 10k to 20k and hope there are no hidden problems waiting to get me.

    For those of you that have rebuilt or done major overhauls, was it worth it? Do you anticipate a lot more life out of it? Would you rather have put a Gen 4 motor instead of a Gen 3? What else has gone wrong after fixing up your beloved Gen 3 Prius?

    I want to rebuild it and get 3 to 5 years out of it for the $6,000, but my wife is ready to just get a newer car. I could use some insight from people that have made this move already or have practical experience in this way. The vehicle has brand new tires, new rear hubs, no major rust or damage.

    Help?
     
  2. AzusaPrius

    AzusaPrius Senior Member

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    I have done exactly this, replaced engine and cat and do not regret it at all.

    I would rather keep the car I already paid for and just keep it running than buy a newer car and have a car note and full coverage insurance I have to pay.

    You can sell it for more with the new parts than lose money on it with the bad parts.
     
  3. theheapstoe

    theheapstoe Junior Member

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    I was hoping you would respond! I had seen you in a lot of similar discussions. Did you end up going with Gen3 or Gen4? I would be doing the install myself, but a full EGR deep clean sounds SUPER nice.

    How many miles was on it when you did the swap? How many miles now? Any other issues coming up?

    My only concern is the hybrid battery (but I guess a rebuilt one is only 2k?). I would be worried I would put all this effort in and then my battery would die, haha.
     
  4. Grit

    Grit Senior Member

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    Sell and buy a $65,000 EV, I’m just saying a member here would say
     
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  5. JC91006

    JC91006 Senior Member

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    Remember at 12 years old, many parts need replacement on the car. After you put in the $6000, you have the HV battery to worry about, brake actuator to worry about, suspension, electronics, exterior/interior condition, and brakes etc. So you'll just have to take all that into consideration.
     
  6. AzusaPrius

    AzusaPrius Senior Member

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    I went with same type of engine, so if I was to sell it there would be no questions.

    Got it from hybridpit.com you can use my code "azusa" to save on the engine.

    All has been pretty normal since and its been a year and about 20kish miles later

    If your HV battery goes out just use the projectlithium link on my profile to get yourself the best battery a prius can have.

    The cat was CARB legal Magnaflow.

    This prius glides like butter and Im getting summer mpgs right now with the help of a short ram intake I just got.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    I’m trying to understand why the engine needs replacement; the code is exclusively catalytic converter related?

    because the Cat’s problems are due to runaway oil consumption??
     
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  8. Tombukt2

    Tombukt2 Senior Member

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    If you've got 120 $140,000 on the car you're heading into head gasket repair territory rather than do head gasket repairing on an open deck engine to me it would be smarter to replace with JDM and get lower mileage engine and a transmission I could have done my engine transmission and the catalytic converter here where I live for about $3,600 comfortably with some money to spare The engine and transmission were only like 1350 The catalytic converter even if I paid retail from the dealer would have put me at what $3,600 bucks or so this is not installed it was 800 to put the engine and transmission in and I would have put the catalytic converter on myself in the shop or in my yard for all I care I do realize you're paying retail and may not be able to do any of this yourself or you haven't shopped very hard or.
     
  9. Grit

    Grit Senior Member

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    And I thought mechanics are the ones we avoid And we DIY because they recommend out if the blue parts and services.
     
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  10. Tombukt2

    Tombukt2 Senior Member

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    On a Gen 3 I just look at the miles If it's above 140 you're in a danger area of the head gasket leaking even minute amounts can be catastrophic rather than spending $3,000 or so to fix that nonsense head gaskets every seal you can see EGR reaming and cleaning you could just replace the whole engine and the transmission with like same with about less than a third of the mileage for I don't know last year it was about $1,300 I don't know I don't think any of this stuff is doubled over that time matter of fact I think my engine went up about $200 since then the last time I spoke to the JDM people this stuff isn't new so they can't raise their prices because of supply chain issues etc etc they can only go up when shipping container movement goes up or shipping prices which some of the JDM companies probably own their own shipping setup so.
     
  11. Tombukt2

    Tombukt2 Senior Member

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    Are any of the people here on list old enough or remember a company called ATK that opened in the '80s?
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    True.
     
  13. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Replace car.

    While a repair like that is certainly possible, I think you're just too likely to hit another expensive system failure (air conditioning, brakes, ???) before another 100k elapses afterward.

    Might as well take advantage of modern safety and further improved economy, and call it an investment in your marriage.
     
  14. Tombukt2

    Tombukt2 Senior Member

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    No with cars like these that are reasonably well made to begin with like the Gen 2 I'll always take the repair. The Gen 3 made this a little more of an uneasy decision to make but even with the Gen 3 other than the engine head gasket problem the brakes and the AC are easy to deal with with JDM parts too most people here discussing costs are discussing what it cost to drop it off at the dealer I get that but we here don't ever do that so we don't have those problems and costs
     
  15. AzusaPrius

    AzusaPrius Senior Member

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    I know you can bet safely on 10 years with a fresh rebuilt engine and new legal cat.

    When the battery quits or when you want to have a better prius than others get a lithium battery from projectlithium.
     
  16. theheapstoe

    theheapstoe Junior Member

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    Wow, that's a lot more responses than I expected. Let me clarify a few things.

    1) I did my research. I'm not buying a low mileage engine as is, so head gaskets about to go bad are not the issue I am worried about. I replaced my own head gasket last winter and it's not a hard job anyways. The engine I will buy has been torn down, all gaskets replaces, honed, machined where needed, the new Toyota piston heads and rings installed, and then reassembled to specifications. I'm not about to pull something from a scrap yard and hope for the best.

    2) The price I listed isn't because I didn't do research, it's because of the quality of the engine I will be getting with the new parts. I have chosen to have Hybridpit install the engine too because as part of their service, they clean the entire EGR system, which I don't want to do. Shipping alone was going to be at least $400, so I figure the extra cash just means I lose less of my own time and risk in the process and get something extra too.

    3) Yes, P0420 is a cat code, but the fact of the matter is that I don't want to spend $3000 on a new CA cat just to gunk it up and ruin it. My engine is only getting older, it's not going to just get better on it's own. I figure, I can replace the engine for less than a new car and reduce the oil consumption, which is the root of all these evils we see in the Gen 3. Consumption, EGR gunk, throttle body gunk, need for oil catch cans, PCV gunked up, cat converter ruined...if I stick my fingers in the dyke without rebuilding it, eventually it's just going to cave in.

    4) My biggest worry was addressed and is my only hesitancy, which is other major systems starting to blow. Hybrid battery is a great one, but even if I have to replace that, combine that cost with the new cat and engine and it's still cheaper than a lot of these lower mileage used cars. The AC is a good point, but I'd love to hear more about people that have actually had that problem. Suspension and other repairs like that, well even with a new car I will have to put in mechanical work, so I expect to have to spend something more on this car in the next 100k. I didn't know about a brake booster issue.

    So the question still remains and I'd love to get more people weighing in too.
     
  17. JC91006

    JC91006 Senior Member

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    If your aim is to get another 100k out of the car, I would just fix everything as it comes up. You have a lower mileage engine and you've already done the head gasket, I would just leave that item alone. Just replace the catalytic converter.

    If you did the head gasket yourself, you're more than capable to do an EGR circuit cleaning. That will take 5 hours on a weekend.

    $6000 is a lot to just throw at a car that's already running in pretty decent condition. I would use the $6000 and spread out the repairs as they come up. Maybe you'll be one of the lucky ones that won't even have to spend that amount of money to reach another 100k
     
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  18. theheapstoe

    theheapstoe Junior Member

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    This has been an option I've thought about, but do we have any data on how long the new cat would last? Or if it will get plugged up from the burning oil?
     
  19. JC91006

    JC91006 Senior Member

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    It has just occurred to me that you are still under CA emissions warranty for the p0420 catalytic converter issue. The car is covered by a 15 year/150k miles warranty for emissions in CA.

    So that catalytic problem is free if you bring it to a dealer (although they will not have a catalytic to give you at this time)
     
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  20. Mendel Leisk

    Mendel Leisk Senior Member

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    What are this problems with your current engine?