2006 Honda Odyssey 3.5 Random Misfire Case Study Part 1 : Diagnosing the P0300, P0301, P0302, Etc. 

Me: No way I'm going to watch a 40 minute video about a misfire Me 40 minutes later: Damn, I learned something, I want to see if this actually works in part 2.

Great video Mike! Lots of lessons to be learned here! Very professionally presented,explained and edited! We are dealing with highly skilled and professional people here,make no mistake about it folks! Thanks again for all you do for us!

as a Honda technician myself i couldnt be more happier with the video and illustration of steps, forsure going to subscribe but also add that you couldnt be more on point with the direction, and i gained a few new ways still, thank you

I want to thank you so much for making this video. I'm in the same boat with my 2005 EX-L, which ironically is identical to the one in your video. After 2 Honda dealerships and an independent shop gave me the run around, I had almost given up hope that a proper diagnostics could be done. Going back to said "lazy" dealership #1 armed with my new knowledge and pray that it hasn't been going on long enough that it's burnt a valve. Oh well, if it has, they'll be fixing that, too....thank goodness for extended warranties! Now I'm going to watch the rest of this series!

My customers issue was a bad coil, replaced, and a month later the new coil went bad which was, fortunately covered, since she knew them and was a great talker. Further, the valve-pan cover gasket was leaking oil into the spark plug area and shorting the plugs out causing the random misfire. Finally, the (braided?)ground-wire from body to the motor was weak (copper was heat-burnt looking, brittle, and easily resolved with replacing and cleaning surfaces. This Honda engine was easy to work on and I appreciate learning new tips from your videos. I have the 720Pro and do back-yard stuff and appreciate learning new techniques to make diagnostics faster to save me work and customers money.

Just finished watching part 1. Superb explanation Mike. I really appreciate all the effort you put into these videos!! 👍👍

What a great video! My 2003 Honda Pilot is throwing error codes for cylinders 4,5,6, and the "general misfire" as well. We bought the car with 100,000 miles on it, and the service records show plugs were done, so I was suspecting a stick coil, but now I think it is the valve adjustment. I don't have the diagnostic gear you do, but I was really impressed with your thorough, logical approach. Nice work!

This is quite possibly the best auto repair RU-vid video I have ever seen. Can't wait to see the conclusion in part 2!

Awesome video. When I took my hands on scope class we were supposed to use the pressure transducer but we ran out of time. Call that you made a video about it. Keep up the good work mike

Fantastic video, Mike. One of the best explanations and analysis of the waveform I've seen. Hope you enjoy doing those back exhaust valves...Always gives me a sore chest by the time I'm done with one of these.

Thank you so much for Video. At 74 yrs old still learning I have a idea on Valve clearance. Thanks again.

Three excellent videos and excellent presentation. Very well put together especially if you own a Honda with a 3.5 like I do. Best presentation I've seen. Thank you

Much better explanation here, than I got at dealership. Thanks

Great lesson Mike! My '05 Oddy was trouble free with 180kmi on it. Never adjusted valves. Amazing engines, valve adjustment necessity aside! On to part 2.

Dude, you are a genius. Your on details. Point every point. Great job. Your video helps a lot. And that gadget you use is awesome. I might get one.

Mike if i could I would give you 10 thumbs ups! This is one of my weak points in engine diagnostics, and this is by far the best explanation of ICPT I have ever watched!! Thanks so much

Awesome information and how clear the problem description was presented and 100% sure how fix that problem. Thanks. I’m very impressed with your profesional ethic

Hey Mike, Great visual with the power point (: Been using the In Cylinder transducers for some time now and MAN what a game changer it is. Couldn't imagine not having it at this point. Really look forward to seeing your take on using the transducers. SO many different thing you can do with them. Lots to learn too. Thanks Mike, another awesome video. Now onto part 2 Lol.. and YES a big change will happen. My guess is 15 to 20 degrees Cheers

I have an 06 Honda Ridgeline with 240K miles throwing the same codes. My mechanic has had the vehicle 3 times and hasn't been able to resolve. This video makes all the sense in the world to me and I appreciate the detail in presentation and clarity in communicating the lesson. Most of all, I now have a direction for repair with confidence that the problem will be resolved. Well done Sir and thank you!

That was a great visual of the piston placement vs degrees of rotation. The whole project was well explained Mike, thanks.

HUGE THANK YOU for this AWESOME video !!! I was able to FIX my 190,000 mile Ridgeline that “couldn’t be fixed”…. YOU sir are a SUPERSTAR !!!

I can wait to see you doing a class for the in cylinder pressure transducers, vacuum and exhaust sensors waveform test!

Fish bite misfire! Awesome video! ! Thank you so much for putting this one out! Magnificent content as usual!

Fantastic video and great explanations. Anyone fixing cars needs to understand the underlying fundamentals. New subscriber(also master/L1) grateful for some refreshers. As the diagnostician at my shop, I break the scope out on occasion, but this ticket also shines a light on some of the problems with boots on the ground and flatrate. At this point with a Honda + miss on front bank, I'd just sell the adjust. If I was wrong my shop would (yes, really!) eat the labor. If you eat 2 out 100 you still come out way ahead. For the FNGs out there, further general confirmation can be had by holding a paper to the tailpipe on a Honda and feeling for a pulse. With this particular car it likely wouldn't be absolutely conclusive given the specs, but this issue is seen across all Hondas with adjustable valves and a sure tell on the 4 cylinders. Re: Cam gears not installed on shafts correctly. This has become more common as more manufacturers use press fit cam gears instead of pins. If you get one of these in, step one is to have the owner asked if the car worked on recently. On something like a Mazda 3 installing the crank pin tool and pulling the valve cover to install the cam bar is generally going to be faster than breaking out the scope and navigating the schematic to find your pin hook ups. You are absolutely right about spark plug choice. Gotta see NGK or Denso. Can't count the number of cars I've fixed by pulling out a brand new set of +4s or splitfires and installing the OEM plug. Great video, thanks.

Hello Mike, truly brain awakening tutorial from theory, diagnosis and the solution as well. Oh, indeed professional presentation as well.

Good job. You made it easy to follow every step of the way.

This video answered so many questions thank you!!!!

You're an excellent educator, Mike. Thanks.

I'm blown away man, so much usefull information on this video . Defenetly subscribing to your channel .

This is great education I don't work on cars for a living but love using RU-vid to learn about stuff I think that pico is worth 10x it's weight in gold for how portable it is and what it can do

Thank you so much for this presentation. Now I have a better idea on how to interpret in cylinder pressure.

That guy is a great teacher..thanks bro.!

That was an awesome presentation my friend. Thx for sharing all this great info

you are a amazing teacher. much respect.

Very well explained! Awesome diagnostic and explanation!

Thank you so much! This is exactly what's happening to mine!

Well explained ! Mike your doing a excellent job keep it up sir.

Damn good video Mike..Damn Good!!!! This was very educational, informative, and professional, you could have sold this job to me for a quick $3000 bucks lol.. You know what you are doing and you know what you are talking about... Damn Good job brother.. I most definitely will be tuning back in with you tomorrow.. Thank you for sharing and caring... You rock Boss...

WOW! This is freakin' awesome Mike!!! When I started watching your video, I have a WELLS t-shirt show up, then my new PICO shows up. WOOHOO!!! But now after watching your video all the way through I realize, now I'll have to get a pressure transducer and I haven't even taken the PICO out of the box yet. Hard to keep up with you big dogs. LOL. This is a great video Mike. Really looking forward to part 2.

Nice video Mike. Haven't got into pressure transducers yet next on my list. Just got a pulse sensor very handy.

You are so good with this video sir. Super nice presentation.

Excellent video! I’m having the same issue with my 02 MDX that has 230k miles

First-time viewer. Super impressed with Mike's knowledge and presentation (I'm a professor, if he were my student, he'd be getting an A). My '06 Odyssey with 220k just threw these exact codes and has the exact same slight roughness at idle. Mike's diagnosis is the bomb. And, he showed me that the proper diagnosis is something that I don't have the time or tools to do. If I go in and have someone like Mike come to me with this kind of information, I'd be totally confident to make the decision as to whether or not to put money into this old van (oh, mine also needs struts, axles, and a couple of other things). Cheers.

Great job Mike and look forward to the conclusion! 😀👍

fantastic explanation Mike really enjoyed this.Thanks

Mike, hello awesome video and info and thank you for taking the time to do all this A+ video . cheeeeeers

Nice!!!Loved every minute of it.

Great video! Very informative and to the point. Thanks!

knowledgeable professional ASE tech. Great information prove the root problem, repair and verify awesome.

Absolutely one of the best diagnostic videos on RU-vid I’ve ever seen. My 2006 Odyssey has nearly 300k miles and is exhibiting similar problems as well as significantly worsened fuel consumption (15-16 mpg driving cautiously). Going to attempt the valve adjustment myself while also doing the timing belt service soon. Just out of curiosity, what scan tool are you using? Keep the videos coming!

Glad i found this, I'll look for the rest and follow. This is most likely one of the problems I'm having right now with my '04 3.5 Pilot. My thoughr on your question was the time would shorten.

I'm working on 07 Pilot with same issue. It has wore me out trying to fix it nice info.

I have a 2007 Honda Polit with a P0302 code and came across your video as I was looking to see how to proceed on my Honda. In short I was so very impressed by your presentation and knowledge, so much so that I watched all 3 parts. A valve adjustment is way over my head and the tools I have to diagnose or fix, but you did provide me with the knowledge to go to my mechanic and know what to ask about if a valve adjustment is required. Can't say enough - GREAT video. Thanks

Very good and technical videos you make for us thanks

Again I really appreciate your input and you're savvy thank you

Nice video, can't way for part II.

Greetings from Puerto Rico 🇵🇷. Excellent video.

Good video, presentation really well done. Thanks.

Outstanding instructional video. Thank you.

Thanks, Mike, an interesting case study.

Great explanation and visuals it really helps.

Hey Mike I'm back. Very interesting case study. Getting ready to watch part 2.

A most excellent video. Great teacher.

awesome job mike

Great information and troubleshooting!

Gotta be careful of cylinder wash if the vehicle dont shut down injector like some do when have a misfire. Great to see the Wps out and being used. Always glad to see videos from you great Job. Im sure you already know about the fuel injector best to unplug if possible its more for others but you may have stated as im still watching.

Very awesome and informative video!

That extremely in-depth. Thanks

Wow! Thank you! I want to get a pressure transducer!!! Such a great lesson!

Awesome well explained as always .thank you

nice video... had customer with 2007 Honda FIT .... stall issue ....when cold.... back out of drive way after one stall... you start back up an never did it again till next cold start . valve adjust fixed it but did kick my ass for couple hours diag time ....

Excellent Mike!!

Awesome analysis

Good and detailed explanation. I hope you will look into possibly teaching at one of the auto programs in your local community college.

great presentation Mike thanks

Very good explanation. Good job like your video

Good class learned a lot thank you

Awesome video, thank you!

This has been happening to my 2006 Honda pilot. When I looked into this before, there is actually a service bulletin regarding this issue of valve lash adjustment and resetting cpu.

Wow this getting way higher than my level, Great learning video I really enjoyed a lot, Just a question here is following this procedure for only one piston is enough to tell us that this engine needs valve adjustment?

Hey Mike! How's it going? Happy New Year to you! Thank you once again for your awesome videos! Your knowledge is greatly appreciated. I have a situation where I'd really appreciate your opinion please. I have a 2005 Honda Accord V6 with 66k original miles. Its has codes P0300, P0301, P0305 and P0741. It has new correct Denso plugs in it. I haven't done anything to it yet because I have it for a couple days. Plus I'm stumped as to where to begin because of the low miles. Your opinion and knowledge will once again be greatly appreciated! Thank you for your time Mike. I hope you have a great week.

Thank You Mike Great Video

Very intelligent explanation

VERY informative young man! ive seen this many times. ive sold valve adjustments on these and misfires still happen... Honda has a class action lawsuit on this engine. Ive heard the rings crap out on them. Honda puts a new long block in them and valve job and adjustment on them... kinda messy... also the valve cover plug well seals leak oil into the plug well tube and does the same thing.... its like pissing in a fan.....

I have had stall complaints too with the 3.5's, those usually have high cylinder leakage

Excellent vids btw

H Great Video. How does the PCM determine that the engine is misfiring from the exhaust valves not closing completely?

Awesome video

very good class Mike

Veru good videos mike, one question to do the valve adjustment?the engine has to be rotate clockwise or counterclockwise? And how do you which way must be rotate it, thank you mike, and cheers from ontario California.

Great video Mike. Is it okay to rely on the Map (8.8) - Baro (28.3) readings in the freeze frame to save the time of getting out the vacuum guage?

great vid mike

Nice one Mike, I'm presently experiencing the same issue but yet to conclude it's the valves. Because mine starts working well then suddenly changes mode by flashing lights and disables three plugs hence vibrating.

Hi Mike. I have 2013 MDX. It has s misfire in cylinder 5. My error code is P0305. 240,000 kms on it So I have done the following 1) Swapped Coil and Plug from cylinder 5 to 6, code remained P0305 2) Tried Seafoam, Redline S1 and Mystery Motor Oil treatment in fuel tank and Engine, issue did not resolve. 3) I got compression test done and it showed low compression in Cylinder 5 120 PSI vs 170 PSI in cylinder 4. Then I got an auto body shop to do all 6 comparative compression test and it came compression is only 25% in cylinder 5 and approximately 75% in cylinder 6. Cylinder 1,4,2 were 100%, cylinder 3 was 92% 4. I took it to Acura and got valve adjustment done, they said it was loose intake valve. It made engine sound alot better and I felt it got power but misfire still shows in p0305. I watched your video and have read forums. Now I am not sure what to try or do next. Any advice and help will be great. What do I try next?

The exhaust valves on my 2010 Odyssey EX-L (vcm engine) were all a little loose except cylinder 5 which was slightly tight. Every intake was a little loose. That was the first valve adjustment for the vehicle and was done at 146k miles.

Son muy buenas lecciones que se aprende de este video

Would this reflect in a compression test as well? Im getting good compression (about 175psi after 5 cranks in each cylinder) but have persistent misfire codes and very negative fuel trims.. especially in Bank 2.

hi mike great video!! question 1... can you get intake vacuum reading by taking the baro number and subtracting the map number to get intake vacuum reading? question 2 why is the map reading not actual vacuum and what is it measuring because it says map vacuum? question 3 what do you do if it has variable valve timing and need to take incylinder transducer reading but dont want variable of valve timing, isnt that a concern? im sure alot of people are wondering this or they havent thought about it so could you please help us out with these questions. much appreciation

is this the same as a weak timing belt symptoms cool info i worked on small engines you are so good at this great info

Great video