How To Diagnose A P0420 Catalytic Converter Low Efficiency Code Plus Exhaust Leak Testing

Catalytic converters don't last forever. In this video, we diagnose a P0420 on a Toyota Camry with over 330,000 miles! Enjoy!

[@glenglene8473]

Catalyst converter still looks good, before to spend money to get a new converter, I would soak the catalyst converter in lacquer thinner, then clean it out. It worked for me the last two times. carbon built up is mostly the reason why setting this code, clean it up it may work again.

[@jlcastille9017]

Great video! I have had people bring their vehicle to me because when their "check engine" light came on, they brought it to someone who claims to be a mechanic but i call them a bonafide "parts changer." They use their magical scan tool that says "P0420" and immediately tell the customer that they need a new cat. Then a few days later, that damn yellow light reappears, so they come to me or another mechanic. 90% of the time (after the cat has been changed), I use my smoke machine (but I like your method with the shop vac also) and I find an exhaust leak pre O2 sensor and repair it for a fraction of the price they paid for a new cat that was just a waste of money. These so-called mechanics should be made to give their customers a full refund because too many are ripping hard working people off and giving the good mechanics a bad reputation. I love to see good videos like yours that show scan tools are just to give you a good starting place to look for the problem and they aren't a "super tool" that tells you exactly what part is failing 100% of the time. Again, thanks for a truly educational video. Well done.

[@rickyaguilar7572]

thanks to people like you . i had a mechanic charge me 700 dollars for a 03 Lexus IS300 MAF . Had nothing to do with the code i even took it in for. (my fault for not trusting my research telling me it is the APPS/TPS) . They gave my car back with the same TPS codes on there and siliconed my Throttle body connectors together so when i had it replaced for 1/3 of the price by a home mechanic-- he had to break the connectors and tape them back. I successfully sued in a small claims court. Thanks to this video i might save 1400 dollars as well.

[@d4ngerous4]

Hi, i bought a premium exhaust and had local mechanic fit it, he did mention that the gasket provided with exhaust didnt fit correctly so he went and got another gasket, i cant help thinking the other gasket is the problem have problem now, i driven for about 3 weeks after fitted now car struggles on acceleration and and engine light came on, so i put my own reader on it, and im getting code p0420 and p0303, i wonder if code p0303 is triggered by p0420??? It just seems odd how the car was fine until i had the exhaust change, i also bought a 02 sensor but dont wanna change it if thats not the problem. I dont have a hoover that blows air how would i do the smoke 1? Thanks

[@iwishtobetexan6060]

Bro give us ur number or place so we can take our vehicle to you please!

[@docimastic]

Everyone talks about exhaust leaks re O2 sensors... but no one shows how to find them. LOVED the shop vac exhaust trick! Thanks for a GREAT video!

[@tzerenny1]

totally agreed, no one in my preview search are showing how to find where and test them. this video did a awesome job

[@marv4242]

Is the car running while you spraying the exhaust down with the soapy water to find the leak?

[@abbasmuhsen2715]

@@marv4242 I think should be not running cold to prevent soap evaporation

[@electric8668]

@@tzerenny1 A smoke test would also work.

[@mxpants4884]

@@electric8668 Sure but a lot more people have a shop vac then smoke test machine

[@rodneyspence7441]

Although there's no physical damage to the CAT and its not clogged, over time the rare earth metals in the CAT will be depleted to the point that the necessary chemical reactions to remove the toxic gases from the exhaust no longer take place. So it basically just wears out. And great tip on using shop vac to find exhaust leaks!

[@GoTechTraining]

Hi Rodney, Great Information! Thanks for watching! Ryan Wilsing

[@bayarearaised1894]

This would be great but I have double duel exhaust tips 🤦‍♂️

[@PandaMan02]

a properly built catalytic converter shouldn't wear out like that.

[@dannydeutsch279]

@@bayarearaised1894 Me too, could one off the exhaust tips just be temporarily tamped off or blocked to create a seal?

[@marymuiruri2436]

,

[@alexandertafoya964]

My God, man. I almost feel like you designed the system yourself. I have not ever heard anyone with as much grace in knowledge as you have explained in this here video, sir. Bravo!

[@mariaamezquita1983]

My car had the same light on; I stopped at pep boys and bought a fuel injection cleaner. The light went off! 👌

[@shanekaut7003]

Best diagnosis walk-through I have seen! Thank you!

[@user-iu1sz5mh5q]

Great video, finally someone that finishes the video all the through final testing. Takes more effort and I appreciate that kind of detail.

[@GoTechTraining]

Hey, thanks for watching! Mike Becker

[@Projekt5.3]

Excellent video. Fellow Tech here and you nailed everything about the diagnostic and covered all the high points that people need to know to work on their own cars. Great job!

[@hyd119]

Hello, I just discovered your channel. I subscribed within the first 20 seconds. Seriously. Within the first few seconds, I noticed how well shot it is as well as the color grading and lighting. Great presenter right from the start. Nice one, Mike.

[@GoTechTraining]

Hey Nill Nill,. thanks so much and welcome to the community :) Mike Becker, Senior Instructor

[@AtlasOutdoorsNE]

Would like to thank you for creating this video. You saved me a trip to the shop and helped me find the leak (exhaust manifold). Thank you very much sir!!

[@GoTechTraining]

Glad it helped! Thanks for reaching out and supporting our channel! ~Ryan Wilsing

[@billyyoder8171]

Thank you Mike. Good job. Have a blessed and safe week to you and your family.

[@GoTechTraining]

Hey Billy, thank you! You as well. Enjoy your weekend! Mike Becker, Senior Instructor

[@PaulHenreid]

Impressive you did not break any bolts with over 300k miles. Good tips on locating the air pocket. It reminds me of the method plumbers and HVAC technicians use to find leaks in gas lines.

[@rudyg2295]

Thank you so much for this video. Clearing my P0420 error code in Camry 2005 with 184K miles. I followed by blowing air in the rear muffler so it pushed all "restriction" on the catalytic converter. First you need to add CATACLEAN in your gas tank (follow direction, drive it per direction). Then I removed the upstream oxygen sensor, then adding blowing air in the rear muffler for 15 min with Shop Vac Exhaust trick. You need to close the opening on the oxygen sensor for 2 seconds, then open it so the air pressure will "push" the restriction. Do it as often you like during 10-15 min. Then install the oxygen sensor back. It make my check engine light disappear (error code P420), and passed NJ inspection for my Camry 2005 with 184K miles. Thank you, save my original catalytic converter, save money, as of now I already drove 150 miles without the check engine light.

[@borkganza9627]

@Rudy G I hope it didn’t come back on.

[@KollynJ]

Did it come back on?

[@MiracleMAX]

Well done Mike, You can only go by the data shown. Imagine if you just went on your gut feeling after looking at the cat substructure - it looked relatively OK & had no rattle. You would end up with an unhappy customer and a lot of wasted time. The data was clear & the diagnosis was spot on. Cheers MiracleMAX

[@GoTechTraining]

Hey MiracleMax, thanks for watching! The data is the key. Without it, we're flyin blind. Mike Becker, Senior Instructor

[@MiracleMAX]

@@GoTechTraining Too true, Mate

[@markjohnson5081]

Excellent! Love the shop vac trick! Always learn something from these video's.

[@GoTechTraining]

Hey Mark, thanks for watching! Put it to use, it works great on single exit exhaust. Mike Becker, Senior Instructor

[@kangokidkidd4037]

I subscribed just on this test wow....i got to try this I got a 2005 Honda odyssey po455

[@nickma71]

It's nice to see the correct technical information. You can't set a 420 or 430 unless the sensor is switching with fuel trim. A leak causes a bias condition, as he noted.

[@GoTechTraining]

Hey Nicma71, thanks for watching :) ~Mike

[@unkemptcasanova1476]

Excellent video. Really cool trick with the shop vac and soapy water. My 2002 tacoma 4x4 is throwing a P0420. Since it has 2 cats, I'm hoping it's either a sensor, or air/exhaust leak. Will test those before buying a whole new cat.

[@p1epoppa]

Flawless victory on the shop vac trick!

[@johnturner8829]

Good to see you Mike. Great info as always. Thanks.

[@GoTechTraining]

Hey John, thanks for watching! Mike Becker, Senior Instructor

[@weldingjunkie]

Nice job Mike I liked the shop vac and bubbles genius. Lots of 420 codes going around, nice to see sometimes even visual good looking cats aren’t efficient enough. Thanks for sharing

[@GoTechTraining]

Hey Welding Junkie, thanks for watching! Glad you liked the shop vac test :) Mike Becker, Senior Instructor

[@dannysautorepair]

Great video sir, thank you for taking out time to explain it in detail. Excellent

[@dompedro112233]

VERY informative! Thank you for explaining everything!

[@dnlmachine4287]

338,000 miles and didnt break any bolts = Toyota build quality + owner takes care of the car + your proper removal technique. Great vids, keep it up! Stay gold.

[@michaeldvorak5556]

From what I have read and viewed else where, use a scanner to monitor the live data for both of the O2 sensors. When the car is still cold, the output O2 sensor will mimic the input O2 sensor. Once car reaches the operating temp, the converter starts to do its job, and the output sensor will go to the steady line. You can also use a laser temperature gun to measure temp at both in and out pipes of the cat when at operating temp. If cat is working, i.e., burning the residual fuels, the output will be hotter than its input by quite a bit.

[@wyattoneable]

Perfect timing. I'm stuck in a hotel with my Jeep in a Amarillo, Tx. auto repair shop for a large oil leak. What else to do but watch videos. I like your way of finding an exhaust leak. It was a great visual for KZbin as well. Great fix too Mike.

[@GoTechTraining]

Hey Wyatt, hope the hotel's AC works well! That doesn't sound like a fun reason to be stuck :( Mike Becker, Senior Instructor

[@throttlebottle5906]

Jeep.. there's your problem :))

[@mike-yp1uk]

This is awesome you get to talk without someone butting in.

[@timsain925]

Thanks for the video. Im not a "car guy", just a "cheap guy". Its nice to see how the O2 lines should look on the scanner.

[@jccarnut]

That is a great test ! I have a exhaust leak "tick" that has been driving me nuts. No codes , only when cold , smoke isn't a option. But I have a shop-vac and bought the wife a bottle of soap just the other day. Pure genius ! I thank you Sir !

[@anthonyliu6374]

what was your fix sir? I am having the exact same symptoms on my sisters 2010 Camry. trying to help her on this.

[@philliphaessig]

@@anthonyliu6374 I have the same thing. Going to break out the vac n soap as soon as we get above freezing.

[@marianogonzalez5708]

Same I also have a tick at cold start usually isn’t very noticeable at operating temperature. P0420 code, I swear I think it’s the exhaust manifold gasket leaking…it’s a 2017 Ford Transit connect.

[@squadman3376]

Take home lessons: Japanese cars and parts are excellent. You are a real pro mechanic and a great instructor. Well done !. The shop vac / soap test.....so simple, so effective !!

[@GoTechTraining]

Thanks so much! Mike Becker, Senior Instructor

[@christopherbarnes7289]

Im going to use that method to find exhaust leaks from now on that is a brilliant method.

[@davidhahn8583]

Nice work Mike. Really enjoy your videos and teachings.

[@GoTechTraining]

Hey David, thanks for watching! Mike Becker, Senior Instructor

[@michaelm9621]

Man, I would have never thought about pushing air into the tailpipe to find an exhaust leak. Thank you

[@biglefty08]

Could this possibly introduce debris into the combustion chamber 🤔

[@hardkore360]

@@biglefty08 I would think that the muffler chambers would most likely catch any large debris from reaching that far

[@brentowen9480]

@@biglefty08 probably a good idea to dump all the garbage out of the shop vac before using and turn it on for a bit before connecting.

[@kenpeek4380]

Thanks for showing me how important it is to raise RPMs to above 2000 for sensor to show faulty Cat converter.

[@ptinker106]

Great video with excellent troubleshooting steps. One of the better videos out there. Keep up the videos.

[@williammason7092]

I enjoy watching you and Eric o you both teach me a lot us old timers need a lot of help with the newer vehicles

[@GoTechTraining]

Awesome, glad to hear it William! Thanks for watching. Mike Becker, Senior Instructor

[@Alniemi]

WOW you just may have saved me over 1000 dollars for a new cat! I have never been so excited to see bubbles out of my header before! Ordering exhaust gaskets now! Fingers crossed. THat trick with the shop vac really blew my mind, its so brilliantly simple! like most great ideas are.

[@highlifegoodlife5400]

It's been 2 years have u had to get new cat or did welding the leak fix ur problem

[@Alniemi]

@@highlifegoodlife5400 I realized that the 96 subaru in my county is exempt from DEQ, so I got a "test pipe" and deleted my cat and im good to go!

[@highlifegoodlife5400]

When u delete it do u still get codes? And what u do with o2 sensors

[@hugoheredia5311]

Thanks for sharing your knowledge, it's very helpful. When I was working for General Motors in Mexico, I visited a GM assembly plant at Janesville Wisconsin. It was an awesome experience. Now I live at El Paso Texas.

[@GoTechTraining]

Hey Hugo, thanks for watching! That's awesome! That plants been closed 13 years already :( Mike Becker, Senior Instructor

[@Gigilador]

@@GoTechTraining where are you located in Wisconsin? I have the same code P0420 with a 2012 Nissan Sentra

[@richborzea4589]

Great video. I have learned so much by watching your presentations.

[@GoTechTraining]

Hey Rich, thanks so much! Glad to hear it :) Mike Becker, Senior Instructor

[@alexlevkovych7759]

Short and informative, like it!

[@gregjones8501]

I liked the vacuum trick! 👍🏾 And I was thinking oh snap (literally) no broken bolts on this one? He lucked uppppppp‼️😂 But either way good job and very detailed and to the point video!

[@GoTechTraining]

Hey Greg, thanks man! Didn't win anything in the lottery though :( Mike Becker, Senior Instructor

[@gunnarroseberg9879]

Mike, I've found that "Mr. Bubble" is just not given enough credit in the auto repair industry. Great as you've shown, also great for exhaust pipe weld integrity check, AC leak check, and a poor man's fog machine! (Much faster than fogger).

[@GoTechTraining]

Ahhh yes Gunnar, Mr. Bubble is great :) Mike Becker, Senior Instructor

[@lukehudson9684]

Man, would have LOVED to see what the inside of that bad cat looked like! Thanks for the awesome video.

[@GoTechTraining]

Hey Luke, thanks for watching! Next time i'll snap some pics Mike Becker, Senior Instructor

[@parochial2356]

Mike, thanks for another great vid! Please keep them coming.

[@GoTechTraining]

Hey Parochial2356, thanks, will do! :) Mike Becker, Senior Instructor

[@bmatthewlouison7439]

Mike, what did you do to cure the leak showed in the soap test? Did you replace a gasket or what?

[@SmittySmithsonite]

WOW, 330k!!! Sweet! Sadly it looks like there's nothing built today that will make that distance anymore without major engine work (timing chains, mostly it seems). If there is, it will be Toyota, for sure. That's a great exhaust leak finder - great idea! 😎 I've used my cheap paint-can smoker on exhausts several times. It does work, but it's harder to see where the smoke is coming from. Much easier to see bubbles. I just did a '06 Corolla cat, 137,6xx miles - the top of the cat had blown right out from rust. The rest of the system wasn't a whole lot better, either. Replaced everything from the cat back. A little different design on this one - I didn't have to touch the header. The cat was bolted to the header underneath. I also got both the flange nuts off after getting them cherry red, but the studs were destroyed. Had to feed a bolt in from the top, while balancing the assembly on a lift jack stand, and attempting to tighten with my left hand. The classic reach-around, lol. After a few choice words were shouted, I got it tight and leak free. 😁

[@GoTechTraining]

Hey Smitty, crazy right? I agree, 300K plus may be a thing of the past. Ahh yes, the "choice words" the go-to tool in the mechanics tool box that always get's the job done. I keep mine in the drawer right next to the flying wrench and the kicked over oil drain bucket ;) Mike Becker, Senior Instructor

[@mikechiodetti4482]

I like your "find the leak" test Mike. Maybe it was a California car that got moved to Wisconsin? Anyway, good fix. Like your new shop! WOW! Beats working in a house garage or worse, outdoors! Hope you're all well. Stay healthy.

[@GoTechTraining]

Hey Mike, thanks! We see a ton of Cali emissions cars here...not sure why. Thanks, the new shop is nice...just need to get a ceiling in and some insulation work done. Got a VW to sell to fund it, haha! Mike Becker, Senior Instructor

[@acarl-lo5tg]

I think across the United States there is a high demand for well used but still functioning automobiles. With greater income disparity lots of folks with lower paying jobs need any form of transportation that is somewhat reliable and will get them to and from a job and is in the $1000 -$3000 price range. That would mean a vehicle with 200,000+ miles and is 10 or more years old. Any car driven in the northern "rust belt" that fits that criteria will look like "Swiss cheese" (pun intended). But there are lots of these cars in the southern states and California where road salt induced rust is NOT an issue. You cannot get much trade-in value in their local domains but used car dealers can afford to pay a little to a southern state dealer for the vehicle and ship it north, sell it and make some profit.

[@mike-yp1uk]

Hi Mike glad to see you got your own channel.

[@utronful]

Great job explaining, and that manifold looks more like a HEADER❤‍🔥

[@kirkwilliams5740]

Thanks for doing this video, your experience is at the highest level.

[@GoTechTraining]

Hey Kirk, thanks for watching and commenting! Mike Becker, Senior Instructor

[@kirkwilliams5740]

@@GoTechTraining Yahshua Hamashiach blessings to you my Brother, you're Most welcome.

[@macculp981]

Thanks so much for this vid. Bottle of soapy water is a much better place to start troubleshooting the 0420 code.

[@GoTechTraining]

Hey Mac Culp, thanks for watching!! Mike Becker, Senior Instructor

[@tmph1814]

This is one complete job, thank you very much👍

[@ZealotZabay]

Thanks for sharing the shop vac and soapy water method! Just found two of my exhaust leaks.

[@GoTechTraining]

Sweeeeeet! Glad it helped! Mike Becker, Senior Instructor

[@J.T672]

Nice job mike , like how easy you made it to diagnose . Good work .

[@GoTechTraining]

Hey James, thanks for watching! Glad to hear you enjoyed it. Mike Becker, Senior Instructor

[@J.T672]

Hi mike , can you remind me which video had , igf, igt ,12 volts all being scoped. I think it was lexus/Toyota

[@frankgonzalez24]

Another way to tell if the cat is bad is by using a thermal camera or infrared thermometer to measure cat inlet and outlet temps. Cat outlet temps should be higher than inlet temp on a good cat. If inlet and outlet temps are the same, then it usually indicates the cat is bad.

[@GoTechTraining]

Hey Frank, I have heard that teqnique as well. I used my FLIR C3 camera with the old and new cat. I was unable to see a temp difference. Maybe it was just the angle? I wasn't able to get a very good shot on the cat. Mike Becker, Senior Instructor

[@throttlebottle5906]

run time is a factor, cold star and check before proper heating is a factor, also is the engine running properly... bad sensors can throw off the heat cycle by computer staying in open loop or bad A/F ratio. which we all know can kill cat.converters as well as skew temperature readings by far

[@danlarson8731]

Thank you Mike. I'm in CA with a 2006 Camry 2.4L PZEV that is throwing the same P0420 code with 363,600 miles and just replaced the original AF and O2 sensors. Will check for exhaust leaks next and possibly replace with a new CAT....:(

[@GosWardHen98]

Thats one of the best Cat Vids ive viewed because at 90k my cat is starting that useless phase, even though it runs perfectly. The p0420 error code is constantly tripping the Engine light. Seems its best to change mine if I can get a good price for doing it. Thank you, you know your stuff, a real petrol head.

[@JimmyMakingitwork]

Good technique. I use a stethoscope I drilled and added a section of 3/16th brake line to for checking exhaust leaks. Works for intake leaks, pulley noises and wind leaks in weatherstripping as well in many cases.

[@GoTechTraining]

Hey Jim, sounds like a cool tool! Thanks for watching. Mike Becker, Senior Instructor

[@williammason7092]

I learn a lot from you and Eric from south main auto

[@GoTechTraining]

Hey William, that's awesome! Eric has some great stuff! Thanks for watching. Mike Becker, Senior Insturctor

[@garfieldwilson4065]

This video is so clear and easily understood.

[@rjeromej8149]

Great job with that diagnosis; a lot of Technicians just use reported codes and start firing the parts cannon. Different method with the shop-vac; I use my smoke machine(s) to check for Exhaust System leaks.

[@pantheroofroblox669]

What about the leak @ the flex pipe? Did you replace it with a universal weld in or did you get the ok to get a new direct fit with the whole assembly OEM wich includes flex and converter? Nice video👍

[@yourlocalalexis4578]

thank you for the vacuum shop tip.... Hopefully i can return the smoke tester i just bought from Amazon, lol

[@melvinrubio2278]

Definitely using this method to find a leak in my 98 Tacoma. CEL came on and the code was P0420 and going this way first before I purchase a CAT.

[@mikeburton1733]

Hey Mike. Great job on that 420. I usually blow smoke up the tailpipe to find the leaks. Same idea. Wow that shop looks huge!!!! I'm sooo jealous.......

[@GoTechTraining]

Hey Mike, thanks man! Same idea, for sure. Yeh, i'm spoiled ;) We moved last October. Got my shop...44x72 :) It had a small section already partitioned, thats where the VW series was shot. The big side is a blank canvas and 44x40. Can't wait to start building on it!!! Mike Becker, Senior Instructor

[@HarryMac-Scotland]

Nicely explained, really liked the tip for finding the exhaust leak - have you thought about an induction heater - probably okay with the torch for an exhaust but saves a load of worry about melted wiring, hoses and plastics.

[@GoTechTraining]

Hey Fraser, thanks for watching!!! I have thought about them a lot. I'd really like to get my hands on one, but I also struggle pulling the trigger due to the cost. I have a torch, it does 98% of what I need. Brake lines and fuel lines would be nice to have that inductive heater for sure though. Someday! Mike Becker, Senior Instructor

[@ronyyecla1402]

6y

[@ebidbay3711]

This is very educational video and well edited to the points. Thanks. Out of curiosity, maybe it's good idea to replace the catalyst converter for the vehicle. For the same situation with P0430 and leak, do you have to replace the converter? Or simply fix the leak? Thanks in advance.

[@mxpants4884]

Fix the leak, clear the codes and then drive it enough for the catalyst monitor to pass (I am assuming this is your personal car, So I would just wait and see if the light comes back on, and If it does check the codes again. If the same one comes back it could be an O2 sensor or the catalytic converter. While you're fixing the leak make sure the wires from the O2 sensor are in good condition. At that point you would need access to live data to distinguish between them. Catalytic converters are a repair that will often cost $1,000 or more. Before you replace one it's important to fix any engine issues first or you'll trash the replacement very quickly. (Days or weeks.)

[@antoniotrujillo547]

Hi Mike, good video and good tip on finding gas leaks.

[@checkitout007]

I enjoyed the presentation. Learned some new ideas. On the down side i did not get to see how bad was the donut gasket when it fell out on the video those can cause a major leak when under load drive

[@mikejohnson465]

Great tip on finding exhaust leaks

[@GoTechTraining]

Hey Mike, all that hot air that you have, you probably don't need the shop-vac, right? haha just messin' with you. Thanks for watching :) Mike Becker, Senior Instructor

[@yipchitaywonga]

@@GoTechTraining Clever indeed. Though would there not be a risk of blowing debris/carbon/catalytic particles into the cylinders?

[@GoTechTraining]

Hey Yipchi, I suppose there is a slight risk of that. It would only happen on the cylinders with the exhaust valve open and it would have to be very small. Mike Becker, Senior Instructor

[@dodgefree1400]

I had to literally junk a 98 Camry xle at 138k miles because our local mechanics are totally incapable of basic diagnostics. Same code and already replaced the converter. V6 loaded model too. All these local clowns can do is parts cannon you. They all wanted to replace it again despite overwhelming evidence it was running way rich. The car could not pass inspection.

[@GoTechTraining]

Hey Patrick, that's not good! Sorry to hear that. I hope you can find someone better to work on your vehicles! Mike Becker, Senior Instructor

[@DGSantaFe]

Just bought a Scion TC n it gave me P0420, awesome video, I appreciate it!

[@GoTechTraining]

Right on! Good luck with the repair!

[@TheWilferch]

Amazing......I have a Scion xA, ...288,000 trouble free miles....and it's throwing a P0420 code. I hear an "exhaust-leak" that sounds incredibly like your car here....a "far-away-jet-engine" noise that rises and falls with throttle position. I found no other vid like this...and the sound you captured , like mine. I had the exhaust "doughnut" replaced at the exhaust manifold where it meets the exhaust pipe....using the spendy Toyota gasket...and the jet noise is still there....and so is the P0420. I used the Scotty Kilmer trick of adding the 1:9 ratio of lacquer thinner to gas, and the code is still there. car runs great both before and after doing this. I also replaced the downstream sensor with a new, OEM style, NTK/NGK brand...as I was getting PO138 before and now it's gone with the new downstream sensor. PO420 is still there and I fear I'm in for a new cat. Will review this vid with interest !!!!!!! ....... fingers crossed.

[@mikedickman6369]

Just found your channel and subscribed. Did you repair the exhaust leak at the flex pipe? I wonder if that was causing the O2 sensor reading and if you had fixed that you might not need to change out the cat.

[@JuanMorales-ks4ll]

so sad he didn't answer but i think he said is after sensor 2 still affecting to give it codes

[@eduardolecea6703]

Excellent Video Mike!! and Great Idea to simulate exhaust leaks. Two questions: Did you install OEM Cat and What OBDII Equipment were you using.....Thank you!

[@GoTechTraining]

Hey Eduardo, thanks for watching! This vehicle was diagnosed using my Autel Elite. I installed a Direct Fit Cali Emissions aftermarket cat. Mike Becker, Senior Instructor

[@Dlaniger1977]

@@GoTechTraining where can we buy that direct fit cali cat emission? Please advise thanks

[@noland1516]

I'm watching you from Puerto Rico thanks for the video!

[@GoTechTraining]

Hello, Thanks for reaching out!

[@johnriley215]

Thanks. Great helpful video!

[@MrDrumstick86]

Nice, helpful video. A question! What did you do to the massive leak underneath with all the bubbles? Did you change that part? Was it attatched to the catalyst converter you changed? // Thanks!

[@hotroddreams3130]

He should change it because my daughter had the same car with the flex pipe leaking exhaust fumes inside the car while she was driving. She started feeling tired while driving and until I got in her car, I could smell exhaust fumes while driving. I replaced it and all was good after that.

[@richard1835]

Great method and use of the ShopVac. Never tried that before. O2 sensors will get lazy over time and Catalyst efficiency will decrease alot especially for a vehicle that is high mileage. The Catalyst system can still be 85% efficient and still throw a code because government regulations mandate a higher percentage on efficiency so as to warn the driver of the vehicle. Most of my customers do not care about replacing converters because of an efficiency code as long as the O2 sensors and the engine management system are functioning properly. Thank you for a great video.

[@GoTechTraining]

Hey Richard, thanks for watching!!! :) Mike Becker, Senior Instructor

[@engelbertmaier2853]

Very good explanation. I always learn a lot from you. Love your channel. Greetings from good old Germany

[@GoTechTraining]

Hey Engelbert Maier, thanks for watching! Sorry, not a Euro car in this one ;) Mike Becker, Senior Instructor

[@moo.johnference869]

Thanks for the information on something so troubling

[@sergeilutzak2479]

The only thing I would suggest adding to the information given in this video is what the numbers are that you are looking for, for both the O2 sensor range and the short term fuel percent range. I realize you are looking for a constant 'steady' number for the O2 sensor, but what if it were steady at 0.1V instead of 0.7, for example. Also, with the short term fuel range, what the numbers should be for lean and rich conditions. Thanks...great video.

[@borkganza9627]

I agree it would have been much better if those details were added.

[@Ghassanamer1985]

Hi .sir Thank you it is helpful video Iam from iraq and our gasoline is not good matter .can the bad fuel cause a code p0420 and i use for that a catalytic converter cleaner and the check engine light turn off

[@GoTechTraining]

Hey Ghassan, thanks for watching! Sure, bad gas can cause a cat to go bad. Really anything running through the cat that isn't a good stoich mixture will cause it to fail eventually. Mike Becker, Senior Instructor

[@DjCBlaq]

Great video I appreciate the detail. I'm trying to learn how to use my new scanner to troubleshoot this exact code.

[@davidroquemore2775]

Really cool. Love the test you did.

[@rickrogers2649]

Great tip on checking for exhaust leaks. Do you think we might be able to get a shop tour when it's finished ? Thank you for posting another great video. Stay safe.

[@GoTechTraining]

Hey Rick, thanks for watching! Ohhh I dunno, maybe. That means I have to get it finished, haha! I need a few general contractors to come by and get it done in a hurry. Winter is coming! Mike Becker, Senior Instructor

[@jesselyons2002]

Had a feeling it was a california car when I saw that mileage. Did you fix the pipe that was leaking ?

[@GoTechTraining]

Hey Jesse, thanks for watching. The customer chose not to fix the rest of the exhaust. The goal for him was to get this vehicle through emissions for as cheap as possible. Mike Becker, Senior Instructor

[@rafaelmonzon1429]

Great video. I seen the shopvac trick on another channel and it helped me to find a similar leak to the one that was shown here. Unfortunately just like this car I need to replace my bank 2 cat. I just hope the bolts come off without the need of a torch cause I don't have one of those.😬

[@junruner]

Beautifully and clean explained 👍

[@juancarloshernandezbastien8827]

Ojala puedan hacer el programa en español saludos

[@avsararas7969]

We own the same car, still driving... the main reason on ours was the mild amount of oil burning issue which renders the converter to become inefficient in a matter of 100k miles or so. I heard most of those vehicles suffer from the same problem which is indeed caused by first 10k miles neglected maintenance, especially oil and air filter change skipping right after purchased brand new. Personally I am very glad to see EV cars getting more common and those we drive now to phase out. Dealing with all those complicated systems to meet emissions is a big burden IMHO.

[@GoTechTraining]

Hey Avsar, thanks for watching! Oil burning can definitely cause issues with the convertor. Mike Becker, Senior Instructor

[@jeremyanthony9300]

Excellent job Mike. Way to go again.

[@GoTechTraining]

Thanks man :) Mike Becker, Senior Instructor

[@larrypoe9496]

You my man are a very smart cat ! Thank you .

[@PhillyDee215]

Bottle of soapy water is one of the best diagnostic tools u can use💯

[@GoTechTraining]

Hey Philly, thanks for watching! Chrisfix calls it soapy wadder, or something like that, right?! haha! Mike Becker, Senior Instructor

[@PhillyDee215]

@@GoTechTraining yup😂

[@brianszuch6774]

what diagnostic tool are you using?

[@tylerfukuda]

Autel Scan Tool

[@1977jelliott]

Great vid, Mike. I watched last night but forgot to leave a thumbs up and comment. Just a tip for future, I have had P0420 thrown on vehicles with a faulty secondary air injection system, that do not show leaks on a smoke test or bubble test. It's a trap for young players 😉

[@GoTechTraining]

Hey Jake, thanks for watching and coming back to leave a comment! Ohhhh secondary air injection systems can throw a wicked curve ball into P0420 diag. Good call. I hope I can show that in the near future! Mike Becker, Senior Instructor

[@gedionsamuel2256]

I got that curveball dealing with an 06 E350 Benz that had a faulty secondary air pump. Now I’m dealing with a 2013 Ford Flex throwing a P0420 & P0430. Took the front cat off and just like your video the honeycombs looked clean & intact. No rattling either. 175K miles. I don’t believe this car has a secondary air injection so should I assume the cats are shot? Unfortunately my scanner is down, updating messed something up. What’s strange is I also noticed an almost 1.5” air gap between the rear cat and downpipe flange while I was down there. I was going to assume that possible leak might’ve caused the problem, as I did remember a slight vibration at higher freeway speeds (though it’s an assumed correlation), BUT according to your video, since it’s technically “post-cat” that it might not be the reason for the codes!? Or am I mistaken? Any help would be tremendous.

[@ksauto1]

love the idea of using shop vac to find the exhaust leak! question though on the finished reading-it looked like it was flat lined about .83 volts-that seems like almost full rich??? I would think it should be closer .45?

[@skyleestapleton1888]

What would cause your catalytic converter to not work anymore just had mine replaced and that code popped up again with the engine light

[@maggiejacinto6064]

Misfire spark plug or 02 sensor Currently doing this

[@TheThreeLeggedChair]

Ya great idea, I would crawl under and feel wind with my fingers..

[@GoTechTraining]

Hey, thanks for watching! Put it to use, it works great! Mike Becker, Senior Instructor

[@automedic9781]

That’s how I do it too, but I really wanna try this now haha

[@loktom4068]

I do it on a cold day and you can see warm air emitting out the cracks.

[@automedic9781]

Lok Tom would love to try that, but it’s 80+ degrees 10 months out of the year here haha

[@edaguirre7267]

Omg this is the first time I see a guy from Wisconsin you make me think in the cooler guy from television

[@victoryvisiontour]

Great explanation and video coverage. Thanks!