DTC- P0304- Prius V 2016

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by Garry20-20, Aug 2, 2020.

  1. Garry20-20

    Garry20-20 New Member

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    Hello Everybody,

    I am in situation here. My 2016 Prius v with 1,75000 Kms had spark plugs service due.(manual says at 1,92000 Kms). But I decided to change it myself because I felt that I had to push my gas paddle hard while accelerating. There were no jerks or vibration while driving.

    So I bought the OEM spark plugs from the dealership (Denso) and changed them. The old spark plugs were not as bad, no oil at the tip etc. Yes, the plugs came off hard. So, I decided to put some anti-seize (copper based), very small, the size of rice grain, away from the spark point.After changing the spark plugs, I felt the improvement in the acceleration and the pick up.But the car was mildly vibrating off and on while driving.

    There was no check engine light. So, I decided to attach my OBD2 Reader. That showed no specific DTC but showed misfire in cylinder 4.I thought it might the coil as I did not changed the coils.

    There was no engine coolant leak, no inverter coolant leak and the engine oil level was same.
    I decided to rule out in the order :-
    1 Spark plugs
    2 Fuel injectors
    3 coils
    4 cylinder compression
    5 EGR system

    1) So, First, I decided to rule out the spark plugs.I opened the fourth cylinder spark plug. It seemed clean as there was no Anti-seize at the tip, beside on the threads. I cleaned the threads with the clean cloth and re-installed the spark plug with the required 13 ft pond torque.

    The vibration did not go.

    2) To rule out Fuel injector of 4th Cyl, I try to use fuel injector cleaner named STP.
    I put in the fuel tank, filled it with gas and drove. I did not feel any improvement. Vibration was of same nature. After driving about 160 kms, my code reader detected P0304.
    The quality of vibration remain same even after driving above 500 kms. So, Fuel Injectors needed further investigation.

    3 To see coil, I decided to swap the 4th cyl coil with the 1st Cyl. BEFORE swapping the coil, I cleared the DTC codes. The vibration remained. OBD showed the misfire at 4th Cyl with no Code.

    After driving about 200 kms, the same code P0304 came Now, I am left with checking fuel injector or the cylinder itself.

    5) EGR- I checked my EGR Pipe, that was about 90% open. So, I doubt the EGR cooler blockage. (Although, I never changed or cleaned it)


    I want to take out the 4th cylinder Fuel injector and clean it .

    I was wonder what should I use:-
    1) throttle body cleaner
    2) Braker cleaner

    3 ) Carb cleaner-
    not safe for plastic (as the injector is plastic)
    4 ) MAF sensor cleaner

    How can I Discharge fuel system pressure? Do I need to take out any fuse?


    Do I need to remove negative terminal of 12V battery and/ or Hybrid battery connections?

    I need your kind suggestions. Thanks
     
    #1 Garry20-20, Aug 2, 2020
    Last edited: Aug 2, 2020
  2. Prodigyplace

    Prodigyplace Senior Member

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    There is no 4th Gen Prius v. 2015 and newer had additional safety for crash tests but that is all. My son has a 2015 Prius v.

    it is basically a larger heavier Gen 3.
     
  3. Garry20-20

    Garry20-20 New Member

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    Hi Prodigyplace,

    Thanks for your reply. Mine is 2016 Prius V. I think its 4th generation?

    Regards
     
  4. Garry20-20

    Garry20-20 New Member

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    Luxury
    Hello Everybody,

    I am in situation here. My 2016 Prius v with 1,75000 Kms had spark plugs service due.(manual says at 1,92000 Kms). But I decided to change it myself because I felt that I had to push my gas paddle hard while accelerating. There were no jerks or vibration while driving.

    So I bought the OEM spark plugs from the dealership (Denso) and changed them. The old spark plugs were not as bad, no oil at the tip etc. Yes, the plugs came off hard. So, I decided to put some anti-seize (copper based), very small, the size of rice grain, away from the spark point.After changing the spark plugs, I felt the improvement in the acceleration and the pick up.But the car was mildly vibrating off and on while driving.

    There was no check engine light. So, I decided to attach my OBD2 Reader. That showed no specific DTC but showed misfire in cylinder 4.I thought it might the coil as I did not changed the coils.

    There was no engine coolant leak, no inverter coolant leak and the engine oil level was same.
    I decided to rule out in the order :-
    1 Spark plugs
    2 Fuel injectors
    3 coils
    4 cylinder compression
    5 EGR system

    1) So, First, I decided to rule out the spark plugs.I opened the fourth cylinder spark plug. It seemed clean as there was no Anti-seize at the tip, beside on the threads. I cleaned the threads with the clean cloth and re-installed the spark plug with the required 13 ft pond torque.

    The vibration did not go.

    2) To rule out Fuel injector of 4th Cyl, I try to use fuel injector cleaner named STP.
    I put in the fuel tank, filled it with gas and drove. I did not feel any improvement. Vibration was of same nature. After driving about 160 kms, my code reader detected P0304.
    The quality of vibration remain same even after driving above 500 kms. So, Fuel Injectors needed further investigation.

    3 To see coil, I decided to swap the 4th cyl coil with the 1st Cyl. BEFORE swapping the coil, I cleared the DTC codes. The vibration remained. OBD showed the misfire at 4th Cyl with no Code.

    After driving about 200 kms, the same code P0304 came Now, I am left with checking fuel injector or the cylinder itself.

    5) EGR- I checked my EGR Pipe, that was about 90% open. So, I doubt the EGR cooler blockage. (Although, I never changed or cleaned it)


    I want to take out the 4th cylinder Fuel injector and clean it .

    I was wonder what should I use:-
    1) throttle body cleaner
    2) Braker cleaner
    3 ) Carb cleaner-
    not safe for plastic (as the injector is plastic)
    4 ) MAF sensor cleaner

    How can I Discharge fuel system pressure? Do I need to take out any fuse?


    Do I need to remove negative terminal of 12V battery and/ or Hybrid battery connections?

    I need your kind suggestions. Thanks
     
  5. Prodigyplace

    Prodigyplace Senior Member

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    Nope. For 2016 the regular Prius was the first and only vehicle using the new TNGA architecture.

    There never was a Gen 4 Prius v in North America before it was discontinued.
     
  6. rjparker

    rjparker Senior Member

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    I would change #4 plug before doing the injector. If it was running ok before you changed them you may well have a bad plug. Also be sure you did not mess up on the coil swap test and reinstall #4 on #4. I might do it again but swap three with four.
     
  7. Garry20-20

    Garry20-20 New Member

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    Hi rjparker,
    Thanks for your reply.
    I took out newly installed #4 plug for visual inspection and looked fine near the tip already.There was no oil at the tip where spark occurs.
    Does visual inspection is not enough ? Just asking for curiosity.

    Later, when I found #4 Plug dry, I swapped #4 Coil with #1. Even after that, #4 Was misfiring.

    I don't have any new plug me as dealership closed due to civic holiday.

    Can I install old plug and see??

    Thanks
     
  8. Garry20-20

    Garry20-20 New Member

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    Sorry, I forget to tell, before swapping coils, I marked them. So, there is less chance of error.
     
  9. rjparker

    rjparker Senior Member

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    Yes a new plug could have a short internally. Use an old plug. If I am going into again I would do another coil swap at the same time.
     
  10. Garry20-20

    Garry20-20 New Member

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    Thanks for your reply,

    Just now, I started my car and tried to hear the clicking sound of the fuel injectors (Specially #4) just to know if its present or absent.

    All the four fuel injectors were giving the clicking sound that ruled out any mechanical defect (but did not rule out any blockage)

    Now my plan is to swap the #4 plug with the old one and check.

    You just mentioned about the coil swap at the same time- I mean with which cylinder?
     
  11. rjparker

    rjparker Senior Member

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    Three and four would be good.
     
  12. Garry20-20

    Garry20-20 New Member

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    Thanks

    Just for confirmation, the location of the #4 cylinder- Is it the one which is nearest to the EGR pipe.

    Because when by OBD reader gave me code P0304- does that mean the physical location of the cylinder or the firing order of the cylinder?

    LIke in this image:-
     

    Attached Files:

  13. rjparker

    rjparker Senior Member

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    Four is on the right (egr side) as shown in the drawing. Firing order is different and largely irrelevant for your issue.
     
  14. Garry20-20

    Garry20-20 New Member

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    Thanks. Got it.

    Does it mean that if the issue is with spark plug, than after swapping it with the old one, car will not jerk instantly ? or I would have to drive for few kms and wait till the computer of car will register new information.

    Thanks
     
    #14 Garry20-20, Aug 2, 2020
    Last edited: Aug 2, 2020
  15. rjparker

    rjparker Senior Member

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    Clear codes. If it was the plug and you changed to a known good plug it will run correctly immediately. If its the coil the code will change from po304 to po303 assuming a bad coil was moved to cylinder three. The best thing to do is to try it and then report back. At this point its speculation.
     
  16. alanclarkeau

    alanclarkeau Senior Member

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    You could try putting all 4 old plugs back in?
     
  17. Garry20-20

    Garry20-20 New Member

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    Hi Alanclarkeau,

    Thanks for your kind suggestion. I swapped my previous #4 cylinder spark plug with the new #1 spark plug but the problem persisted (jerk of the car).


    Update:-

    I took it to the neared Toyota dealer:- After initial test, they called me and told me that its the intake manifold and EGr gasket that needs replacement.

    I don't know whether its IM holes blockage due to carbon or any crack etc . I could not see the mechanic today itself as it was late in the evening but planning to talk to him tomorrow.

    At the dealership, they told me that the sparks etc in the engine are fine, ( I cannot tell what does he mean by etc here- will see mechanic tomorrow).

    I took his words with the grain of salt.

    So, will update as new information pops up.

    Thanks
     
    bisco likes this.
  18. bisco

    bisco cookie crumbler

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    im is generally part of the egr circuit cleaning. it will be interesting to see what they say
     
  19. Garry20-20

    Garry20-20 New Member

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    Hi Bisco,

    Thanks for your comments.

    I was wondering if IM is intact ( i.e. there is no crack where air leak is possible), but is clogged with carbon, and I decide to clean it

    myself, Should I switch off 12v battery and/or HV battery (Reason for removing- to avoid mess up with any ground etc.) ??

    or

    clean IM without removing the batteries?

    Thanks
     
  20. alanclarkeau

    alanclarkeau Senior Member

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    This doesn't make sense. The car was driving well - mostly. Spark Plugs changed. Then Vibration.

    Now mechanic is saying that "the intake manifold and EGr gasket that needs replacement."

    If it were me, I'd go back to Square ONE - put all the old plugs back - and see what it's like then.
     
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