DTC- P0304- Prius V 2016

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

 

Hi Prodigyplace,

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

Regards

 

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

 

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

 

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

 

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?

 

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:-

 

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

 

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

 

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