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Car chokes up when gas engine warms up

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Johnny007, Mar 5, 2022.

  1. Johnny007

    Johnny007 New Member

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    Hello to each and everyone. I need some help please. This started happening yesterday to my 04 Prius with 209k miles. When my gas engine starts warming up from a cold start, after a couple of minutes of driving, first it felt like a slight jerk then as I continue driving it starts acting like my car is gasping for air choking and losing power. However, when it switched to electric motor, it runs normal.So I cleaned the MAF sensor to see if it would fix the issue but to no avail. I test drove it this morning with a cold engine, it started off good but when the gas engine warms up it starts choking again and lose power. Any help would be greatly appreciated. Thanks
     
    #1 Johnny007, Mar 5, 2022
  2. JC91006

    JC91006 Senior Member

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    I’d suggest you clean the throttle body as well. Then reset the car by disconnecting the 12v battery negative for about 10 seconds. See if there’s improvement after that
     
    #2 JC91006, Mar 5, 2022
  3. PriusCamper

    PriusCamper Senior Member

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    Do you have any warning lights when its gasping/choking?
     
    #3 PriusCamper, Mar 5, 2022
  4. Johnny007

    Johnny007 New Member

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    Thanks for the suggestion, i'll google how to clean this part and see what happens.
     
    #4 Johnny007, Mar 5, 2022
  5. Johnny007

    Johnny007 New Member

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    For a couple of months now i've been ignoring the triangle of death and check engine lights due to a bad hv batt temp sensor so not too sure if it should give me a separate warning light but no additional warning light besides the 2 that i've mentioned.
     
    #5 Johnny007, Mar 5, 2022
  6. JC91006

    JC91006 Senior Member

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    Are you certain the red triangle is not for a failed inverter pump? Do you have codes?
     
    #6 JC91006, Mar 6, 2022
  7. Johnny007

    Johnny007 New Member

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    I'm getting codes P0A9C and P3000 according to the dealership and claimed they cannot find what's throwing those codes after their initial diagnostic so they asked my permission for an additional 5-8 hour diagnostic ($160 per hour I think) which I politely declined.
     
    #7 Johnny007, Mar 6, 2022
  8. PriusCamper

    PriusCamper Senior Member

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    You really don't want to trust a stealership on this... The easiest way is to get one of these: Hybrid battery diagnostic and repair tool for Toyota and Lexus and keep it in your glove box to read and clear codes via Dr. Prius app on your phone. This will also allow you to monitor three different battery temp sensors so you can be sure the faulty temp sensor is the problem rather than something else.
     
    #8 PriusCamper, Mar 6, 2022
  9. dolj

    dolj Senior Member

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    I'm not sure why they would need another 5-8 hours – this should be a fairly straightforward diagnostic. You have a temperature sensor problem. This could be a sensor, wiring, or the ECU itself.
     
    #9 dolj, Mar 7, 2022
  10. edthefox5

    edthefox5 Senior Member

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    Probably the hybrid battery fan is clogged. Or the plug rotted out from bad leak in cabin.

    Sounds like the ice air cleaner is clogged too.

    Get a flashlight take the trunk parts bin out so you can get to the spare tire then look in the bottom of the 12 volt battery hole see how much water is in that hole. There will be water.
    If you have water battery has to come out and water drained. Then the battery fan plug must be checked.

    Hybrid battery needs to be pulled too it’s amazing if it’s the original.
    It must be checked unless you like getting stuck somewhere at the worst possible time. Driving around with the RTOD is foolish it will get you.

    Hope you have AAA.
     
    #10 edthefox5, Mar 7, 2022
  11. JC91006

    JC91006 Senior Member

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    which dealership did you go to? What a crazy rip off situation for diagnostics

    If you are close to Rosemead, there is a smaller shop there that can fix your problem. They don't charge those crazy diagnostic fees.
     
    #11 JC91006, Mar 7, 2022
  12. Johnny007

    Johnny007 New Member

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    I finally cleaned my throttle body 3 days ago and after, disconnected 12v for 10 secs. It ran smooth, no codes for about 20 miles then P0302 pop up. Googled it and says most likely spark plugs and coil packs so I ordered 4 new spark plugs and 4 new coils and just to make sure a new MAF. Replaced everything mentioned and test drove the car. After a mile, I felt a mild thud then it's like turning on my christmas lights. Red triangle, check engine, VSC, small orange triangle with exclamation. To top it off, the engine isn't engaging, just drove with battery. Good thing I was close to home. Plug in OBD reader and got P0302, P0113, P0353, P0354 and P0102. Just to be sure, I checked the coil pack connectors and MAF connector all of them are tight and secure. Any ideas what going on with my prius? Thanks guys and sorry to be a pain.
     
    #12 Johnny007, Mar 12, 2022
  13. JC91006

    JC91006 Senior Member

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    Whenever you are troubleshooting a single issue, in your case a cylinder 2 misfire, you should concentrate on that cylinder first. Don’t replace all sorts of parts as that’ll make it hard for you to really know what went bad.

    did you buy original denso/ngk brand spark plugs?

    did you buy original denso coil packs?

    The maf sensor didn’t need replacing, and if you did replace that, hopefully you used original parts?

    you still have a cylinder 2 misfire, so maybe all the parts you used didn’t do anything to improve your situation, might have made it worse with new symptoms.

    your next area to check would be fuel injectors
     
    #13 JC91006, Mar 12, 2022
  14. Johnny007

    Johnny007 New Member

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    Noted, concentrate on one issue at a time.

    Yes. original Denso parts. I will reuse the original MAF and see if it'll clear out some of the codes.. Lastly, will look into the fuel injectors. Again, thanks for your help.
     
    #14 Johnny007, Mar 13, 2022
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