'09 Prius with multiple cylinders misfiring, or are they? 

The type of terminal you back-probed at the IGT (Ignition Coil) should have the probe inserted to the exterior side (OD side) of the connector seal. That way you insert the probe beside the seal not through it. Going to the inner side (like in this video) pierces a hole in the seal. To visually confirm this concept, remove a terminal from the connector and check it out. Good job Pat

Anyone who devalues information like this shouldn't be turning a wrench. Even for us shade tree mechanics; this is solid gold.

Nice video, VDD. Parts changers have ALWAYS given mechanics a bad name. You are 100% when you say training is key. Many moons ago, when i was a rookie, i was told that the VOLTAGE REGULATOR (external, mechanical & electronic) and ALTERNATOR were a matched pair and must always be sold together. Well, i learned later that the reason shops did that was usually because nobody had a clue how to determine which one was causing the battery to not charge, so they sell both. Entire HEI distributors would get replaced because mechanics couldn't troubleshoot if module or pickup coil was bad. I've seen heads and engines condemned because of failed EGR valves; and car owners never knew because I was hired by the shop or auto parts store to sort out the mess, not the car owners. CONSTANT TRAINING saved me from the dark side.

Nice job PJ! Love how your videos are always right to the point no extra fluff or waffling about as they say over the pond.

An excellent diagnostic video. The diagnostic thought process is everything. Thank you for sharing.

Thank you Patrick. Good job. Have a blessed and safe week.

Thanks again for the great info. Know it takes time but you're making all of us smarter!

Loved this one Pat, great video and diagnosis! Pretty wild how horrible those things sound when misfires are occurring.

Great work PJ. Love the use of the wps in the exhaust!

Nice work , right to the actual cause of the miss .

I just found your channel and have subscribed! Excellent walk-thru of your diagnostics! I look forward to more great videos!

Great video! Nice work with the Pico and WPS. Thanks for sharing 👍

Good one PJ, and loved the ending rant😉

Always appreciate your excellent teaching. Thank u!!

Thank you for this video a mechanic shop told me I need a new engine. When saw you video,it thought me a lot.im going to fix my Prius by myself.

I am from South Africa. Here a oscilloscope is not part of any training no matter where u become a tech. If it wasn't for you guys on RU-vid i still would have been just an average tech. Since i started watching RU-vid and learning about an oscilloscope and the power it has, my business has grown immensely. So i agree u need both. And from what i see from u guys an oscilloscope is also not standard equipment in the average repair shop. This should have been a easy repair for any halve decent tech. Thanks for the great share

Thank you! I like seeing how the Picoscope hook ups and explanations. good for guys that don't use it it that often to help figure out the set up. Great diag! And training is paramount. All great guys to learn from.

Great video, thanks. I have a low idle misfire fault on my 2012 prius gen 3, toyota put it on the tester and found multiple misfires, they suggested replacin the entire intake manifold. They didnt really explain how this causes a misfire however and it left me suspicious. My thinking was with multiple misfires and never having changed the plugs that that would be where we would start. But after watching your video i see they are probably spot on.

thats why iam a DIYer for years. great videos.

Great diag. Bad techs are devaluing the biz. They are pissing everyone off. Ripping off customers and have made a lot of places a joke to deal with. Keep ignoring the haters! Keep pumping out good info! Cheers from a Ontario Canada!! :-)

Great diagnosis and video. Unfortunately, you are only as good of a mechanic as you want to be. Laziness and time restraints are killing our industry. Although I am "retired", I still watch all of the RU-vid videos that I can. I am still constantly learning better ways of diagnostics and repairs by the RU-vidrs who graciously take time to share with us. I applaud all of you, great job and service to our community. Keep them coming.

Great video pj! Well executed 👍👍 Can't wait for Super Saturday, it's going to be amazing.

Great job testing

AWESOME/BRILLIANT information and will be excellent to ess how you hook the pico to the car always learn things from you with excellent exceplantion and always enjoyable to watch thanks for sharing and cheeeeeers.

Impressive! True professional

Thanks great video thanks for shearing your knowledge and your time and your experiences

thanks for the info, and the links!

What a video! Nice explanation! Thank you!

Well done buddy. Love this approach and you did a great job on your video.

Oh cool, I just got a Launch dia- gun as well. I'm looking forward to learning about the tool. I've learned so much on RU-vid but I have a long way to go. Good rant.

Nice work PJ. Now I really need to practice pulse reading.

Nice catch! Thank you!

While this isn’t exactly a hybrid-related problem, it’s cool to see hybrids being worked on. There aren’t many youtubers that work on hybrids. I welcome all the knowledge.

Why is Devaluing? sharing and learning let people happy and rich in life.Thank you PJ

Great video PJ. The sharing of information Can't devalue the industry. It is the constant misdiagnosis and bs spread to customers that does that. Some people might become better diyers because of this bit of info and we lose a customer but quite often that little bit of info gives some more confidence than their ability and now requires a larger repair bill. Lol. It all works out in the wash.

excellent job 👍🏻

Excellent job buddy

You're so right!

Awesome work PJ. I dont know how they say youtubers are devaluing the industry. Bunch of haters if u ask me. I'll see u at super Saturday brother. Take care

most excellent video . step by step , precise . the thing that is killing the industrie is untrained techs without the proper equipment to perform the job

Nice video, thanks for sharing.

Fantastic work with the scope!! Whom ever pulled out the shotgun method with parts changing clearly needs a new profession this could be diagnosed with out a modern scope. A coil contribution test would have proved coils were not the problem there goes fire, next compression - a trained ear could hear strong compression , next air - clearly that's not the problem all that's left is fuel and that injector was DOA so an old fashioned scope a stethoscope would have found the dead injector.

Great information thanks, i seen a lot of ignition coils get damage by lean miss fires, only last week was asked to look at a car that would have new set of coils every year and the last year it had two sets, so of course get the scope out and wow the ignition systems was very lean easy to test if you use a scope alll the time so the real fixed for the car was to remove the injectors and test and clean they need to flow 200ml in one minute at 2.5 bar they only flow 140 and one was just 120 ml so cleaned and restest and back to 200ml and no more ignition coils. So keep up thr great work

Great job.

Thanks, nice use of Logical Thought Process,... There are to many parts changers & no LTP, NICELY DONE! .. Also, feel exhaust manifold or get an I.R Temp gun for $20. & save burnt fingers. The cold cylinder is not firing... or disconnect one at a time , the missing one wont make a difference... If its a vacuum leak it will fire ok under load when the it mix requires more air. It looks like the injector seals would be a potential source of leak... High speed miss is different again as ignition breaks down under compression... & Thanks again for lesson on high techtools! ( Retired Field service tech for Yale lift trucks and electric vehicles. ) W/B

Great video PJ! See you at Super Saturday.

Pj as always great video and diagnosis! As far as training goes Vision is on my list! Looking forward to SS! & I absolutely agree with sharing information we know amongst each other. I’ve learned a ton from both in person/online training.

Of course they are. 😜 My 2013 Prius went from 44mpg average after a misfire to 30... and I replaced the spark plugs. Still 30. But I have yet to clean the EGR valve which I feel will help.

Thank you! What a thorough young man. U are an excellent teacher/example. Is there other ways the avg guy who doesnt have your tester or what do u suggest since scanners would show this. VERY nice/thoughtful for u to share this! I subscribe! Thank u.

Great video 👍

nice work thanks

Hi pat , we had a prius with multi cylinder misfires at our toyota dealer , cause was egr sticking also inlet manifold can get blocked up ,especially on taxis. Thanks for video

the missing fuel injector stood out in 2 seconds

It's been years since I've been this deep into a Misfire.

Nice 👍🏽 thank you

Hi PJ, thanks for this video really enjoyed this , you my man are a credit to this industry... By the way how can you isolate just the injector waveform on a fuse feeding a many circuits, Thanks

Great video! I ain’t got pico 💵 but I bought a Hantek and can’t wait to use it. I sub to Ivan and Shrodingers QM too.

thanks

Hi, love watching your videos I'm having the same exact misfire as on this video and I don't have the tools you have, should i change all the spark plugs and coils at this point? Thanks in advance

I have a Toyota Prius 2010 that does not want to start, but when it does start the car begins to shake violently. But normally it doesn't even start. These are the codes that appear P0A0F, P3190, U0293. The battery is charged, I've checked and cleaned the MAF and the ERG, also changed the coils. What would you recommend me to fix the 2010 Prius

Hey, the more information and tips out in the public domain, the better it is for *everyone*. There should be zero excuses for professionals not knowing their trade. Hell, I'm 100% DIY. I buy used cars and keep them running for hundreds of thousands of miles. If a home gamer can fix just about anything, a professional charging a shop rate of over a C note an hour should be able to too. It's all about adding value. People will pay handsomely if they're getting value.

If you don’t mind can you post the brand and model of the items you are using for this. Awesome work man, shows with a little effort you can diag a car correctly the first time! Keep up the good work!

Learned a new trick with my headlight bulb probe.. As that is a cheap boss tester..

Facts. Part throwers are who give us techs a bad name.

Great video. I have a problem with my 2008 Prius and I was hoping you could help me with it. Its throwing a P0047 code. After researching it, I have found that its related to a turbo relay. This car has no turbo. The gas motor shakes when it turns on. I have replaced the pvc valve and spark plugs with improvement. Can you help me?

inspired from you bro God bless you wanna buy a picoscope which one you prefer me dont have any idea alot of sample in the market or if you make video on picoscopre which you have that will be pleasure for us just learning from you bro love from pakistan

hey..Walter..Is there a way to do relative compression test on the prius?

Great video! That was a great technique that I've never seen before. But please, explain why the Prius makes that terrible sound with an engine misfire??

hope this channel blows up good luck! if you ever know of anyone selling a good bidirectional scanner for DIYer guy or an oscilloscope (vantage pro) or anything shoot me a PM

I wanted to know how u did the intake comp power exh overlay at the 3 min mark .. u didnt post a link in the description ..

Great video and btw were you able to listen to the injectors with stethoscope ?

I'm having a similar issue with my 01 Prius. random misfires. no clue what's causing it. I've replaced the injectors ignition coils and spark plugs. Can a bad engine ground or something cause it? or is the engine itself a ground already?

Great vid...what model pico did you use....

You can use a power probe on each coil or you can just pull the lug and stick it in the coil and watch the damn thing spark. If it ain't sparking change it

damn fine scope work. have you stopped to do a simple contribution drop tests?

What is that laptop or tablet you're using? Thanks

👍👍

Wow, I never heard a Prius misfire before. What causes the terrible sound?

👍🏼

Did you fix the problem?

Prius really doesn't like a misfire, from that racket you would expect a rod through the side.

You coming to vision this year?

Does it make some de value by posting this? Yes maybe. Here is my story. I couldn't afford to do class room training and their wasn't their any real training in my state that I could find. If it wasn't for RU-vid and people like Scanner Danner and say you. I would not be were I am now or especially using a scope. Now I went from the low paid guy in my shop to the highest and most valued guy in the shop am at. Plus I'm starting a business. In 5 years. That's thanks to you all! That would of never happened cause I never had any good teachers at my jobs.

One small issue, not sure how the technical info you provided clashes with the simplicity of fuel, fire compression. Hint hint simplest thing to test is fuel, by adding it. Anyone that fails to grasp this point does need more training absolutely.

I don’t think what you share on RU-vid devalues the industry at all! Most DIY people will look at your videos and think it’s out of their wheelhouse anyway. Not to mention you’re using equipment that few have. Your content benefits other technicians. I wish Honda was more scope friendly and made shops buy them! I sure can’t afford a pico.

Valv gone this car , nothing else change second hand engine or opend head nd put new valv, i no this very well !!!

Follow up comment. I tried to go to drivabilityguys, but my computer stopped me with a warning. I saw SuperMario with the same software. I still would like to get it. Does someone else offer it? Thank you again for sharing.

So it was fuel injectors?

Did this guy seriously not clearly explain and show the fix to the problem at the end? Holy smokes

sad thing is all the training in the world wont do ya any good unless you use it. i worked at a place and went to factory training once a year. unless there was a recall or a service bulletin/campaign it was three to 4 years before we would see any failures that needed that training to diagnose. by then you had forgotten most of it. and if you do everything it could be a thousand oil changes in between. training is good. just figure a way to keep it fresh.

Price of that test? I prefer to replace all the parts for 100$ and fix it

but i said he better clear the codes just in case it has intentional shut down of the injectors

I need help, I dont have the credit/money to take it to a shop. I have to figure it out on my own and fix it. I have a 2010 prius doing the death wobble. I just put new fuel injectors , didnt fix it HELP PLEASE

It is frustrating....and for those that don't have a scope, remove the spark plug, activate the injector and watch it fail....smh...this is NOT difficult...STOP BEING LAZY TECHS!!!!

What "vacuum and explosions" to explain how a "explosion engine" works. 🤣 No just making a point it is a "combustion engine" it is silly tot talk about explosions, we are not 4 years old. 😉 The definition of a "explosion" is that it is a UNCONTROLLED event. It is a controlled EXPANSION and timing (ignition), when that flame front of the ignited air and gas mixture is expanding, that is WHAT is happening in the cylinder. The definition of vacuum is that there is nothing every molecule is not in that space at all by being sucked out so there is nothing there. The piston has created a UNDER pressure and not a vacuum. When nobody/nothing has sucked out the molecules! And to be correct that is never happening that the piston is going down in the "intake stroke" and then we have vacuum.. .. never in a 4 stroke combustion engine. It is defined as the "intake stroke" because it is taking IN something. (air and gas in this case). Sorry to be so rude . But going out of your way and then explain to us that you are better than other machanics (that had replaced coils) and are trained formally and have taken courses and so on. And being so high educated, in your specific expertise area and job. And then failing to use more correctly describing wording of how basic stuff work. Make me start to doubt that if someone is so careless of choosing the correct wording, of something they should know by hart. Then is they "sloppy" in other areas also. 🤔 Maybe it is just me or the general understanding and knowledge of the public is so low. That this is the base level they think that they fully understand how stuff works. That makes faulty and poorly wording being "OK"? Just some constructive feedback: Use better wording and maybe then more people will trust you and what you are saying. 👍👨‍🔧 Thanks for the video! 🙏

Wow I looked again at your explanation at ~4 min. That is COMPLETELY wrong. There is no vacuum that you repeatedly are saying and is your so called reason of what we see. We can ONLY talk about overpressure and under pressure. The combustion in that cylinder is not happening ("misfire") and the and therefore there is no expansion happening either. Expansion = increase of pressure (that is what is pressing the piston down that is not happening in that specific faulty cylinder). When that increased pressure is not going out to the tail pipe when we have not ignited the air and gasoline mixture. Then we do not get the expected pressure and we get just the unburned fuel and air mixture pumped out to the exhausts. Those will have lower pressure when they have not been ignited and burned. So where is the vacuum... Wow that were a very bad explanation. When blaming vacuum when it is the total opposite of the lack of expansion=higher pressure and you make up and blame lower pressure occuring because of vacuum. 🤔