Very good and thorough explanation No excess material and self promotion. Very good use of automotive vocabulary

Excellent. Fix the CAUSE. I got a p0420, and every shop tried telling me just replace the CAT for $1,800. NONE of them wanted to look at anything else to find the source of the problem. The problem was severely carbonized spark plugs not burning fuel effectively and leaking liquid fuel into exhaust sytem clogging the CAT. replaced plugs, cleaned the CAT, intake and ran some fuel system cleaners. Been running ever since

First time that I've heard Short and long term explained in all of my 29 years of service. Even teachers and other techs have not nailed it like this bro. Most other people want to be heard for their much speaking instead of making the point clear.

Some folks deserve a subscription. He’s a legend at saving folks money with practical diagnostic skills and great explanation. Make more vids man.

This is the man I want working on my cars....one that can talk the talk AND walk the walk too! EXCELLENT video.

Finally, someone on KZfaq that knows what they're doing. Excellent videos, video, good troubleshooting, good execution

The brake booster pedal trick is awesome. Never heard of that not even from Paul Danner. Great video brother! Thanks

You have a magnificent brain, sir. I've never seen a mechanic explain this so simply. Your understanding of the complexity of the various issues and your ability to articulate a repair response that is so easily followed are beyond commendable. My teacher wasn't even this clear. Thank you for sharing and congratulations on your level of expertise. Have a blessed day and may God bless you and yours always.

Kit, Two weeks of searching KZfaq for diagnostic information on O2 sensors and fuel trim. Finally, You have the best video by far. Very thorough from start to finish.

I really appreciate you with deep technical information that bunches of uneducated in reading of computer diagnostics. All they tell you is just the codes, without telling the course of the issues.

Thanks you for helping to understand and troubleshoot the P0420/p0430 correctly, I wish all car repair shops do the same. I always found shops that only replace parts without knowing exactly the problem. Keep up the good work work. Thanks again

I'm glad I stuck around. I thought when the cats were condemned in the beginning we were going straight to replacement. Great overview of the troubleshooting process.

teaching is a gift and you definitely know how to teach. every child needs a teacher like this man here very simple with his explanations and very easy to understand and replicate. he is making auto mechanic look like a walk in the park 👍

Great, clear, concise PROFESSIONAL information that finds the root of the problem and FIXES the cause, not just the symptoms. Plus, I would bet 99% of most shops would never asked or have found out the engine was replaced and the cats may have had 200k miles on them. Yes my friend you said it, “ fix the cause, not the symptoms”. 👍👍. VERY COOL. Edit, Subbed too.

I love this. You are an excellent teacher. VERY CLEAR EXPLANATION supported with doubtless evidence.

At last!!!!! Someone who knows what they are talking about and is also able to explain exactly how things work in a clear and easy to understand way. Watching the video was an absolute pleasure, thank you, I can now make sense of my own vehicles problems etc.

To be honest with you, the first video watched, I gave you a Post- thumbs up, the second video, I gave you also a Post- thumbs up and then, I have found that you deserve a Pre- thumbs up! Your way of teaching takes me from ground ZERO maybe even less, to a high level. Professor!!!

This showed the most practical and informative diagnostic techniques (I've watched literally dozens of videos that didn't get this practical) for getting comfortable with whether the sensors or the cat are bad! thank you!!!

Thank you for actually teaching how to analyze obd2 data, all other videos I’ve seen aren’t nearly as well explained as this

THANKYOU FOR A VERY CLEAR AND INFORMATIVE EXPLANATION OF LTFT AND STFT AND CHECKING GRAPHS AND WAVE FORMS TO TROUBLE SHOOT PROPERLY YOU TEACH VERY WELL AND IGET IT BEEN A MECHANIC ALL MY LIFE AND AT 65YEARS OLD STILL LEARNING FROM GOOD GUYS LIKE YOU THAT IS HONEST AND LOVE TO SHARE KNOWLEDGE ,GODBLESS YOU THANKS AGAIN

First I would like to start off by saying I watched this video from the very first second to the very last second and I must tip my hat off to you sir. You are very straight forward, informative, precise and honest! I wish I could find a quality and honest mechanic like you where I live. I'm not sure where you're located or if you have any contact info, but I would surely become your loyal customer. The reason I say you're honest is because as soon as you turned that vehicle on after the installation was over with and that check engine light went away... you could've easily fooled everyone and told us there you have it folks the check engine light is gone because we fixed the problem. You sir did not do that. You told us the truth! When disconnecting the battery cable(s) from the battery it essentially clears any codes stored in the vehicles computer/memory (which is true). I respect and admire you for that. I have a 2007 Hyundai entourage limited V6 3.8L and I have a P0430 code. I'm doing everything myself thus far and in doing so I found a lot of cutting corners from every "mechanic" that has worked on my car in the past 6 years or so. I'm not a mechanic by any means and I'm learning as I go by researching and reading. Every shop I have gone to so far... everyone says it's the catalytic converter, but not the two that you changed. They're saying it's the catalytic converter that's underneath the car. No one has done any tests of any kind to determine if it is in fact that catalytic converter. They're just saying it's that one. My gut is telling me it isn't, but again I'm not a mechanic and I could be wrong. The car runs like a champ! You wouldn't think there's anything wrong with it. I do know the fuel is either too rich or lean because my gas gauge is always fluctuating up and down before finally settling and before this code appeared I never had fuel issues. Some times from the muffler I can smell a very rich gasoline like smell. I was also told to first replace the spark plugs and go from there. Start with the smaller stuff before changing the catalytic converter to see where the problem is coming from. I've already changed that and all the O2 sensors, but the check engine light came on again with the same code of P0430 bank 2 catalyst system efficiency was below threshold for a predetermined period of time. I'm just now sure which catalytic converter it could be. Would you be able to share what name brand and model # obd2 you are using so I can look into purchasing one? I'm sorry for this long message, I appreciate your time and the time you put into this video for us. I hope to hear from you soon. Take care!

You're an awesome auto mechanic. You're really an excellent teacher. The best video I have really liked to watch. Detailed explanation on the issue was amazing. So thank you so much for doing what you're doing. I like auto mechanics who are knowledgeable and above all honest. All your customers must be lucky and thankful to have you as their cars' mechanic.

I really appreciate the exact way that you explained how the graph diagnostics were operating before and after the repair, nicely done!!!

what a video. not only is this guy a knowledgeable and qualified mechanic, but he also knows just how to make a video that covers all the bases. great job!!

YOU ARE A GURU OF A MECHANIC AND OF KZfaq SIR. YOU SPEND ONE HOUR OF EVERY DETAIL ON THE SUBJECT. THANK YOU. GEORGE Z

This is the most thorough diagnostic video on o2 sensors and catalytic converters I've seen. Congratulations.

Really excellent explanation of how to diagnose catalytic converters issues. I love the trick of pumping the brakes to make the engine run lean. Now I need to get a scan tool that will show me real-time data streams. (I just bought a cheap one that doesn’t have that feature, am going to return it and upgrade.) Thanks!!!

Hello K, I would like to point out the difference in temperature between the intake and output is not near the 100°f degrees you stated it should be. The temps on the old defective Cat were: Intake: 390.5°f Output: 334.4°f A difference of 56.1°f The temps on the NEW Cat was Intake: 404.3°f Output: 336.2°f A difference of 68.1°f The difference in temperature between the old and new is only 12°f degrees. It seems to me this is not a accurate method to determine if the catalytic converter is defective. I think your video is great. The detail and examples you show are top. You excel in quality the art of putting a great video together. Thank you

Very deep information and a lot of details that haven’t found in many videos. Thank your for explaining.

Because of this video I subscribed to your channel. Excellent well explained class about catalyst converter. A real substance and knowledge, well done. Professional Auto Mechanic!

This is one of the best videos I've seen on these codes. Good job sir!

I sooo wish I saw this video before I let this shop replace my converter a week ago. My vehicle now sounds like a lawnmower since the aftermarket one they added does not seal properly. Amazing job explaining for someone like me who knows bare minimum about vehicles.

You are a legend. Im getting a P0420 code on my 13' Audi A4. Ive watched countless videos and didnt know where to begin. Now i know how i can go about diagnosing this problem. I was going to start with replacing O2 sensors before the cat. But thanks to your informative video i can now test before blindly going about changing parts. Thanks a million. You are a CHAMP! earned a new subscriber too.

Man, what a lesson. Thank you for sharing so efficiently the knowledge

This video is excellent, I wish other people's videos would be like yours. I hope you keep making great videos like this one!

brilliant explanation of how to troubleshoot O2 sensors, fuel trims and the brake pedal pump trick is epic, thanks for teaching us!

You are the best explainer in the case, Sir!

Man..!!!! I can t thank you enough. For this 👍 ..... the way you explaining I tell you right now you the best ever 👌.....thank you again...I'm going to subscribe now .

Good Job !!! Very Complete Explanation of What the Problem was and Step by Step Process to Fix the Issue !!!

Absolutely fantastic video. As you say, I want to address the cause, not just the concern. Now I know how. Thank you!

Thank you greatly for all the knowledge. I have a scanner and got this code code when I scanned my car.. (didnt show up on my dash as engine light), I have been wondering why my car has been sluggish and little bit poor fuel eco. You taught me enough in this video that I can read the scanner and try to see for myself if I have a bad cat or just the sensors first. Your a great teacher, I've subscribed and am looking forward to learning more, thank you! 👍

Best video I’ve seen on Cats so far. Awesome job. Thanks for sharing.

This video was so beautiful I had to subscribe. Nicely done, you took your time but explained everything in detail great teacher all-some.

I learned how to read scan tool data and apply it to fixing the problem. I took notes on diagnostic and testing progression. A very logical and mechanical instructional approach, plus a demonstration of how to apply it to the repair. This is better than the lecture videos that others make where they try to show you how much they know.

Had the same issue (code p0420 bank1) on a 2000 Acura Integra but car ran perfectly fine. Heard about CATACLEAN and decided to give it a try as my mechanic said it was the cat that was bad. Poured in the entire bottle ($27.99 at AutoZone) when I had 1/4 tank left (per instructions) and drove it for about 100 miles. I noticed a boost in power right away but CEL was still on, I had to reset it and drive another 20 miles or so and when I checked with scanner again, all monitors were ready and no CEL. Took it to my smog station and passed with no issues. Great product which if it wouldn't have worked, this was going to be my next step.

Excellent in depth video. I now know how to check for cause of failure and what failed instead of just replacing parts. Thank you.

You're incredibly talented with a big intellect Maestro!🙌🏼 it was so detailed it deserves a subscription for sure, love it!

Excellent source of viable and understandable information specifically for this code. Thank you so much!!

Best video explaining how to diagnose! Awesome job

Nice job. I wasn't sure at first, but you are a technician indeed.

Gracias Amigo. Muy buen video. Pude aprender a leer los graficos del scanner para el codigo P0420. Los tips para diagnosticar y la metodologia para ir descartando los posibles problemas. Repito, MUY BUEN VIDEO!!. Tienes muchas condiciones de didacta. Te deseo toda la suerte del mundo. Continua con estos videos!! Vale la pena cada minuto.- Abrazo desde Argentina.

Really great video. Just had emissions failure and the P0420 code. Its an old car and we don't want to throw money at guessing the issue, this really gives some great pointers. Wish you were local!

Fantastic overview of ruling out the potential causes for converter failure prior to replacement using the scan tool.

Very thorough explanation, and very thorough diagnosis. Thanks for posting this.

You are so smart. You explain everything very well and clearly. I don't know anything about diagnostic, but I'm understanding bit by bit

Just Thank You! Subscription earned! I hope you’ll continue to make these thorough teaching videos… and still get some work done.😉

very good explanation of how the system works and the sensors! i enjoyed watching the video !

Excellent video....I subscribed ....your good, very good....I have been an auto tech over 50 years, have seen miles of videos, this, is the best!

You my friend are one cool cat...alytic converter. I learnt so much from this video. I couldn't stop noticing how many times you said catalytic converter if full, where cat might have sufficed. But, your knowledge and generosity in sharing it let's you off in my book. Would have been easier to follow tho 😆 Keep up the good work brother. Watching and rewatching. Everyday is a school day. Oh and subbed. Top man. From Rob in UK. ✊

My favourite section, K Diagnostic you are too much and well done. Habib Auto

Great video. Wish you were here in Raleigh, NC. Keep up the great work.

I skip a little bit but, most of it I watched all the way. I have a 05 Camry that showing p0420 and p2423. Now I have more understanding what's going on in my car. Glad to know where to check and test. Also I'm glad I don't have to remove all the stuff in my kind of car🙂. Thanks! I will subscribe. Good video repair and teaching. Have a good one🙂👍🏻

Thorough explanation. Very good job.

the depth of explanation is awesome! thanks

Best I’ve seen, great tip about missing brake pedal thank you

best catalytic converter video on KZfaq! But that vehicle is sure a PITA to work on.

I highly appreciate the true professional know how, very logical approach and elaboration of each step and very easy to understand way of explanation. My salute to you brother. Keep it up 👍👍👍

Thank U very much , U are very honest to explain every thing honestly , happy to watch your interesting videos , happy to get much information like that , you have nothing without interpretation for every things , God bless you friend , your sincerely from Egypt , Greetings

Truly excellent explanation, so well understood and communicated. Well done and thank you!

your explanation speed is excellent you can be a good mechanic but to explain the way you do not too many mechanic can do thanks man im telling my friends watch K diagnostic

Great job clear and concise info👍

I love the way you go through the process of testing O2 sensor response by pumping the brake pedal. I have a -29% ST Fuel trim reading. Also a p0420 and a p0170 pending on a 2011 2.4L Sonata. No check engine light but driver said car struggled to accelerate. Once it got going it wasn't as bad.

Best mecanic ever seen.....you do your job with passion💯👏 You're a teacher, bro.

Really great presentation! I learned a lot. Thank You! Brilliant pump brake to test O2 sensor 2!

Mate, that was an awesome video with all the explanations. Legend! Thank you

Hi, Deo Kitoko. Once again, awesome learning experiences. Big thanks from Seoul.

Very well explained. I just bought a new scan tool autel mx808ts and I can now analyze the date accurately. I have a friend with the same trouble code in his kia grand carnival 2006. The car still runs good but the check engine light stays ON. I’ve been telling him it could be just a bad O2 sensor or worst will be a bad cat converter. Thank you for sharing this video. Cheers

Hi, it's one of the best explained auto repair videos I have seen. Keep it up

fantastic video. one of the best o2 / cat videos ive seen, thanks!

Today is first time and it's absolutely awesome video.... Thanks for your explanation Cheers

Outstanding mechanic, explains things in very simple terms!!! Easy to follow!!!

Excellent , thorough explanation. Kudos to you sir!!!!

Nice! Didn't realize how the brake booster actually worked. I didn't know it gets extra air when you pump the pedal. But it makes sense since I one day replaced one because it had a massive vacuum leak by the brake pedal.

He knows is stuff most definitely blessing to you 🙏

You re the best technician god bless you.

I wish all cats were this accessible. My Dad recently gave me a 2005 Chrysler Pacifica Touring SUV 3.5 and it has a PO420 bank 1 trouble code. He had the bank 2 cat replaced a couple of years ago. Car runs great, plenty of power and acceleration, tail pipe has pressure etc. but you can definitely hear the cat rattling when you give it some gas. I changed the oil in it today and that's really the only other issue I have found other than a routine tune up I'll do next week. lets my Silverado come off the road for some needed repairs at least. As always, great video!

"Thank you for sharing your knowledge" God bless you 👏

Thanks for this valuable information; That was a very net trick that you showed on how to check and see if the O2 sensors are operational:

Excellent job. Excellent explanation, easy to understand. Wish I can take my 2008 Odyssey to you. Thanks.😊✌️🙏

Excellent video and data reading on fuel trims and O2 sensors 👍👍👍

Thanks again for another excellent well explained lesson!! Great job!

This is too many great information man thank you, appreciate it.

You are such a good teacher.

Thanks man… Great informative video with precise details… I will be doing some testing before purchasing new converters. Thanks again Bro…

Another excellent video! Very good information.

❤thank you so much for doing a detailed video for cadi and all the other things you done. ❤

This was a very detailed and informative video.

Your video is awesome, I really like to watch it thank you for making this video,

@ 27:17, you said, "the outlet temperature should be a lot cooler than the inlet temperature". I think you mean the opposite. The downstream side of the converter should be 100-200 degrees F hotter than the inlet because of the extreme heat generated in the converter due to catalyzing the NOx molecules apart. That is why the is extra heat shielding around the converter.

Best video on this I’ve seen so far kit