2011 Prius misfire cold under load codes

That is Dr Prius. I can look for an update

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Newer dr prius app finds no codes. So sad.

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Only after it misfires a bunch. Code c0302 comes up then. On the old app. On top of the other ones.
It can start and run fine at stop.
I can drive it down to the stop sign less then a block.
Go to turn onto the street and start to excelerate it starts to misfire. I let off the gas. Then put some gas into it. Misfire. Letoff the gas.
Put gas back in it would be fine.
Sometimes a 3rd time.
If I let it misfire too long code pops light comes on.

So I'm leaning towards air fuel problems. The white plugs say alot about it running lean.
Possibly speed sensor telling computer wrong speed so it might be requesting wrong about of fuel.

Oh yeah more gas I give it the harder it misfires.

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I just remembered. The throttle body plug had a bunch of corrosion I tried to clean off I guess about a month ago. Could only spray it with an electrical cleaner.
They sell a solder in plug I'll try swapping it out with.


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The sensor code is read correctly. I did have that once. But not now.

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Ok I slacked off yesterday since it was cold 64 degrees. Didn't swap out plugs. Today I did first I took tiny drive it was very bad.
Then I swapped out denzo for ngk plugs the good ones.
Put back in ngk coils. First tiny drive it was fine.
This doesn't mean I don't have an Air fuel mix problem. Or the denzo plugs and coils were no good.
It could mean the ngk stuff is capable of burning the mixture and denzo is not.
In the past ngk stuff was known to fire hotter and better.

I've been out of the loop for a long time, So IDrK .

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Ok got out my multimeter.
It seems the 4 new denzo plugs were no good.
3 are no connection
1 was 0.55 mega ohm


Testing original plugs as well 2 sets of ngk plugs
11 out of 12 Say between 3.7k ohm to 8k ohm most a little over 4k
1 plug said ol

I guess new denzo plugs Be no good

Oh yeah question if coils
Well the ngk were able to fire the no good plugs so I say ngk must be pretty good.
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Well looks to me you still can tell if there is a break at least in the secondary coils and probably the primary coil.
Seeing if the transistor works seems not so easy to tell.
Also resistance of the coils could give an idea how much voltage output there probably is.
But seeing an actual dead transistor it would need that testing equipment as you mentioned.
Of course if the transistor circuit is open then one would see a broken transistor.
All I remember about the transistor is that a low voltage will control higher voltage.

I guess the only thing anyone could look for here is if there is an open circuit. An open circuit would definitely mean no good.
Other resistances really talk about how much output the coil is theoretically capable of.

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It is simplified sure. But an induction coil is an induction coil. Be it controlled via transistor or points.
Without examining how many windings and those details one couldn't say an approximate output to spark plugs voltage and amp.
Sure you can't tell if the transistor is working like you can tell points are working.
But the coils themselves you seem to be able to tell the health of those circuits.
If a transistor fails I would think there would be a dead miss in the engine.
But when you're talking about an induction coil a broken circuit has been known to do weird unpredictable things if it's not totally dead.
The measuring of those circuits would eliminate the possibility of those weird things you could be seeing. Not the calculated output just the possibility.
In the past I have seen coils that worked but when measured they was an open circuit. There would be a similar misfire underload situation. This would be due to the coil loosing voltage from having to jump a gap inside the coil itself. It really depends on where the coil is broken I side. If the break is close to the output the rest of the coil could build enough voltage to jump both gaps the one in the coil (loosing energy) then the gap in the plug. But the spark at the plug wouldn't have enough energy to ignite the air fuel mixture under load.

My situation looks to be a broken circuit and high resistance in the spark plugs.

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If the electronics are bad in there I'm sure there would be a dead mis meaning the engine would run ruff at idle.
So yes, correct point. Can only test what you can test.
As stated you could use a laser heat detector on the exhaust to see which cylinder is not firing then change out coil to different cylinder to see if temperature difference follows.
Oh yeah the manual said that.

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Yup it was the OEM spark plugs. Watch out people.

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Sorry the plugs don't say counterfeit in any way.
The idea parts from Toyota are infallible is incorrect thinking.
For example: I bought OEM engine mount from the dealer
It had wrong bolt in it. It kept coming loose.
Oops so much for infallible OEM parts.

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