2005 Toyota Sienna code P0420 Catalyst System Efficiency Bellow Treshold B1

[@LAactor]

Before you go Mr. crocodile! I wanted to express agreement with changing the AF sensor that is inside the catalytic converter because after 200k, it really is time to change it. Toyotas are made to allow "lazy" AF sensors to continue to operate with a wide range of sensing so as to not throw the code to change the AF sensor until it is fully "kaput!" Meaning a dead AF sensor heater circuit (inside the sensor itself). But I recommend the change not only because it may be seized up inside the converter's bung hole, but because of the lazy sensing circuit which causes losses of as much as 5-10 mpg! When gas prices were low, that means you would waste double the cost of the repair every year it was left like that. The vehicle was about 150-175k when it started to do that. So better change it and save. However, the rear one rarely fails. And is outside of the hotzone and is not in the toxic gases with the cat. That one can stay until a code comes. One last point, the reward for reading this far, a secret many people don't know is the manufacturer of Toyota AF and oxygen sensors are a branch of the OEM named.. #Denso. So the part number will be different and also much shorter. But also it is cheaper for the same quality. RA has the part for $117+10 shipping. And remember. Every AF sensor is different. Hundreds exist for all the different engines out there. Make sure you get the right one, not just the cheapest one. Or else you could put an O2 sensor in a hole where the AF sensor needs to be.

[@markn0024]

Congrats on getting the new shop up and running so quickly, Petr!

[@camgere]

Nice video! I just paid $2,000 because of a check engine light on my 2011 RAM 1500. I think it ended up being the gas cap. The dealer recommended every service possible before actually trouble shooting the problem (most was worthwhile doing). Emissions can get pricey. The Toyota Sienna minivan debuted in 1997 (2005 is the second generation). It was developed by Chief Engineer Yuji Yokoya. Toyota takes customer satisfaction very seriously. It is a high priority across the design process from beginning to end. Not just a white paper from marketing that is soon forgotten. He drove the previous generation minivan (Previa?) across all the states of the United States as well as portions of Canada and Mexico. He spent time with American families (and learned how important children are in the typical usage of the minivan.) He developed the concept paper (shijisho, or the somewhat more military sounding “direct order document") that was approved by the higher ups after extensive consultation (nenawashi or buy in) with all concerned parties. The concept paper is intentionally high level, the possibilities to be narrowed (prototyping and set based concurrent engineering) as each module and part is studied in detail. Toyota is notorious for front loading the design process and expecting few or no engineering change orders after the detailed design is started. Yokoya also requested that all warranty repair parts for the first year be shipped back to Japan for analysis and corrective action. (Don’t you wish your car brand did that!) The fourth generation Sienna came out in 2020.

[@cartap22]

I had a code for that catalytic and I took it off and washed it with detergent like Scotty Kilmer said and it worked for me

[@thatdadrz]

Thanks for the feedback did you just use dish soap? I’ve been considering pulling it off and washing it but wasn’t sure if it would work

[@cartap22]

I used laundry detergent

[@cartap22]

I let it sit in it for 24 hours.

[@miriamvivo4279]

On a a/f ratio sensor = 4 wire 2= black test for ohm resistance set on 200 on your multimeter. If showing 1 no bueno. Other 2 are blue and white

[@christophervanzetta]

That’s a bandaid, not a fix.

[@nikovandh]

One should try to replace the post cat O2 sensor first. My vehicle used to give me P0420. After I replaced only the post-cat O2 sensor at 195k miles, the code has been gone for the last 20k miles. I also replaced it on roommate's car that was not completing the drive monitor readiness on the cat 2 years ago, and it went ready afterwards so that she could smog the vehicle. Worth a shot, since shops replacing the cat will want to put new sensors on the new cats. Just make sure any system involved in air/fuel is also working properly!

[@LAactor]

You could also backprobe the sensor wires and check the voltage and ohm readings to determine if the sensor is outputting the correct data or is faulty. If you have a scan tool with live data you can also watch the numbers and see if it's switching correctly. Best is if someone has a scan tool that graphs. You can see if the graph is wild and if it's not normal.

[@nordicpride9708]

The proper procedure would be testing the downstream sensor via a capable scan tool, confirming its faulty first, then replacing the sensor with a Denso unit.

[@TheWilferch]

Good and clear presentation......talking slowly and clearly.....good job.

[@psychodocter]

Gr8 info and nice to not hear the wind rattling the garage door. Thanks Peter!

[@LAactor]

Very thorough video. I like it! Few months prior I just had to do this also but not a P0420 code. It was luckily a code for tat bank 1 AF ratio sensor. Had to argue too much because owner didn't understand front vs rear does not mean the same because these Toyotas have transverse (sideways) mounted engines. I want to point out to people who may be unfamiliar, when Peter said head gasket, it may not be clear to non professional technicians. While obvious to some, others may think it is the engine head gasket, which it is not. He means that is the exhaust manifold head gasket. While most other people would think of the cylinder head gasket inside the engine to separate the water (coolant) jackets and the cylinder heads. This is obviously pointed out by Peter in detail because he pointed out exactly the exhaust manifold, but like my owner who did not understand, the viewer should also know there are many gaskets. But Peter did it correct, I just wanted to clarify because some owners need things explained in great detail because of their limited information unlike a dealer experienced technician like Peter, out man, who has a lot of knowledge.

[@vio2696]

Good job. But there others videos, they show how to solve this issue very cheap way. Your video is very explicative but but without giving any help for poor people. I hope you will find some million guys to follow your way. God bless !

[@workoutrescuewithblakehowe]

Appreciate the video. I have an 06’ Sienna CE with 235kmi and have been dealing with a p0230/240 code for the past 4 years. CEL comes on for a bit, then goes off for a bit. Luckily it’s been off during times the smog test needed to happen (CA). I’m suspecting the cats are about gone but it hasn’t affected performance or MPG at all. Unfortunately, you can’t register a car in CA without a smog, and you can’t smog with a CEL on. Other than that, the car looks and runs perfectly so it’s unfortunate that a code like this pops up because this car can make 300kmi easy.

[@johnaclark1]

$650 is a bargain for a Toyota catalytic converter. Many of those are up in the $2K neighborhood. Congrats on the new shop!

[@huanweili7699]

Ebay is only $120 free shipping. 30 minutes to replace

[@johnaclark1]

@@huanweili7699 yeah, If you like doing the job twice, get a cat from eBay.

[@jos35847]

Wow! Incredible clarity and details!

[@tundramanq]

I like that they positioned the cats where they are hard to steal even though it makes replacement a chore.

[@LAactor]

I'm not entirely sure if they had anti-theft in mind when they designed this product

[@jimv1484]

Wow....outstanding vid. You have given us the knowledge to make our own decisions depending on budget. Very thorough and appreciated. My company owned one of these vans and it was a great vehicle. We got this code and paid the man to fix........the dang code came back not long after the $800 repair......I told my tech to switch to Shell gas.......2 tanks later the code never came back.......my friends and family only use Shell when available.

[@wangofree]

My 01 Tacoma loved to throw the P0420 code. Bosch sensors were junk. Denso O2 sensors took care of this.

[@LAactor]

Correct! You learned the hard way for Toyota don't use Bosch electrical anything.

[@FreedomLover170]

Thanks for sharing your knowledge I would love to see a "how to " video on how a pro would change this out..👍👍👍

[@marcvinette8512]

Would it possible to make a video for the replacement of this catalytic converter? I have the same engine in my Solara

[@andrebombardier3021]

If I have a exhaust leak at the gasket (doughnut) for the catalytic converter bank 1 (pass the cat, before O2 sensor B1) can that leak trigger the P0420 code ?

[@Ngcarson1337]

Hi Petr. As others have mentioned, it didn’t seem clear by the end of the video what specific items you would deem necessary for replacement. Is there further testing to determine if we should replace the sensors along with the manifold/cat assembly? Obviously, if someone has the money to throw at their Toyota, they would replace it all. Sadly, most people are looking for the most economical option, and won’t want to replace a good part “while I’m already down there”. Thanks in advance for your videos and congrats on the new shop.

[@LAactor]

There is further testing that can be done and you can request it if you are paying for diagnostic time for confirmation. Not all shops will apply the diagnostic credit to the repair however. Some things you just know to replace like the AF sensor which is also famous for needing changing. You'll know if you get 15 mpg from a Toyo that should get 20-25 mpg of this vintage, etc. People have had trouble replacing the cat with non Toyota parts. The substrate material is smaller and contains less catalyst like platinum palladium and other converting chemicals so it may not last as long. Or fail quickly.. oxygen sensors can be replaced with Denso's. However make very well sure it is the correct sensor for the location and engine. You can KZbin videos where techs use a Pico graphing scope scan tool to show the operation data of any suspect sensor. But that's good information to know. Some techs and I'm not saying Petr but some like to just like to load the parts cannon and fire and hope it fixes it. So that's always a concern. Might as well start small. But also, a logical approach is the mechanic is doing what the codes say. Unfortunately sometimes the codes say a problem is there but it is the result of a bad sensor like you said. What vehicle maker were these cars you mentioned? It makes a big difference.

[@aquamancrow]

I suggest replacing the bad component(s) vs using the parts cannon method. I had a P0430 code (same as P0420, except for Bank2). My solution was to replace the $18 doughnut gaket that was causing an exhaust leak between the Bank2 cat and the downstream O2 sensor. The flange gasket leak was sucking in air downstream of the cat. The O2 sensor was detecting the unburned oxygen, and pointing to catalyst inneficiency, when in fact, there was nothing wrong with the cat. The gasket was replaced 2 years ago. No further problems. A great video for troubleshooting P0430 / P0420 component problems is this 17-minute video. kzbin.info/www/bejne/iHKmYXhsltWLp5I

[@Ngcarson1337]

@@aquamancrow I really appreciate your breakdown of the situation you found yourself in, along with the video link. We still have an unresolved P0420 code on our Sienna, even after replacing the outboard cat/manifold. Will look into this further and hopefully resolve for good. Cheers, mate!

[@Winslow273]

You can get the Denso brand A/F and O2 sensors direct....for a lot less... Can you do a video on the waveform testing of the P0420 & P0430 that shows the lack of residual catalytic capacity in a 'bad' one versus the waveform for a 'good' one? And then a tips & tricks on removing rusted exhaust manifold bolts without breaking the old studs. 🙂Also curious on your thoughts/comments on why/how these go bad and the typical mileage you see. I have taken several toyotas (01 Sienna v6, 98 & 05 Camry I4, and 08 4Runner) over 300K and this 08 1GR-FE is the first one I have worn out cats on, and both at the same time. It is not burning oil or anything and the cats are not melted or plugged, just the residual curve is no longer there to meet the standard.

[@LAactor]

I would love to see that video too! One can hope. Has Eric or Wes done either of those case studies? Without seeing any of your vehicles, my wild guess (because it is all a guess without mandatory in person observation) is that it's cat poisoning. Be it ethanol that is higher these days in E-10/15 to oil bypassing the rings to so many other reasons. I hope he is able to get the job to change these cats. That can looks well taken care of. Shiny for an 05 with 200k!! I personally have had various years go bad around 15 years more or less and 150-175-200 miles more or less.. it really varies on the driver, maintenance (current and past owner), and even down to how many times in it's decade and a half operation it's been floored or heavy accelerated even. Which affects the fuel ratio. And of too much raw unburned fuel goes into the cat, from doing that or running a bad sensor for too long, then there you go. But AF sensors go bad more frequent than the post cat sensors which don't have the heating element in them. And don't live in the toxic gases pre-cat.

[@agookchild]

tips: change the title of the video to "Bank 1" instead of "B1" and your video will get 100X more views.

[@fastwalker21]

Bank 1 spark plugs may never have been changed. Why not check them first. As the code means below threshold meaning not 100%. Would like to see a fuel trim B1 vs B2 on scanner. On previous episodes you show very worn plugs with no misfires...The B1convertor is smaller and prone for mixture problems. Clean MAF, check spark plugs and filter and replace post O2 sensor first.

[@LAactor]

I noticed someone else day change post O2 sensor first also, why is that? Lowest cost? My understanding was the heaters inside the AF sensors go out more than the oxygen sensors. And especially the bank 1 because it's tucked in the back like that. Heat soaking all the time in the worst way.

[@michaelbrennan7148]

Thank you Peter. Very helpful.

[@gs7865]

It's a good description of many of the parts involved with that code (not all), but goes nowhere explaining the way to fix it, what to look out for, or the other things that contribute to that code. The video just kind of half-ass recommends throwing over a thousand bucks at something, and it might not fix the issue. Kind of bummed about the lack of depth, this was supposed to be a maintenance channel right?

[@plutosforest]

Toyotas around this year are quick to throw cat codes and a few other codes if there is something that's affecting emissions. Annoying, but not annoying enough for me to fix. Older ones and newer ones don't fuss about emissions as much.

[@LittleMama06]

So bank 1 is on the left side or right side?

[@markreynolds3850]

Thanks for sharing this video, interesting information and video

[@alexanderestk]

Had this code for my 2004 4runner v6. Bought a Napa catalyst for like $800? Direct fit. But the metal in thinner so unfortunately my taco tick sounds louder. Definitely will go oem if something like this happens again.

[@aldrintejada598]

So.... Which one is it? The O2 sensor or the catalytic? He didn't even say which part was at fault. Basically just went over what parts are called and the location of things.

[@johnlacroix1639]

WOW very kool great info.,,1st class AAAAAAAAAAA++++++++++++ again great video I liked it a lot keep up the great work.

[@alandust2188]

Is there a way to test a catalytic converter off the vehicle? I have a 2007 FJ , the cat has been changed along with both sensors and I still have a code. 5 different shops have not been able to fix it. Lights are on the dash, I still have the codes and it runs fine.

[@LAactor]

Other than a visual inspection to see if it's physically clogged, not really much you can do unless you have a dyno machine and can run that but at that point you're spending more in doing that that you might as well buy a replacement. If you have it off, you can try "cleaning" it as another user suggested. He said laundry detergent. And then if that doesn't work to try differing progressively more aggressive things. Because you don't want to strip the precious metals off the honeycomb into the bottom of your bucket. Having it on the car would be easier to test. You can use a laser thermometer to find the temps in operation that way.

[@plutosforest]

I'm just living with it in my 04 Sequoia. The vsc, trac, and check engine lights stay on. Pretty sure vsc and traction control are disabled until the emission issue gets fixed. Older toyotas and newer toyotas don't have this problem, they are not programmed as stringent. Don't waste your money on new sensors (doesn't help) or a new cat (waste of money).

[@LAactor]

@@plutosforest I find it strange that Toyota decided to turn on many dash lights even if unrelated to show one problem. Noticed the same on other Toyotas. Had to do a sequence of e-brake lever pulls to deactivate on purpose a vehicle that got in a collision and bent the strut. Although I know your lights are on without you doing that. The only reason Peter is having to care about the cat is because in CA the smog program in most metropolitan counties require the check engine light be off to pass state inspection. Some other states have varying degrees of requirements to pass for certain cars that fall under the majority of the population's ownership. Something like between 6 to 40 years old or something like that, don't quote me. Some inspections are hard like maybe NY. Some are easy like Nevada. I agree with you that if your state doesn't care, forget about it. Although the Federal environmental people would care. Although I think they rarely go after individuals. They go after the big bucks. The shops. There is a trick you can do to make the sensors sit further out of the exhaust stream by drilling out a spark plugs nonfouler and putting that inline. You can search for the videos on here. Hopefully that brings your safety back.

[@plutosforest]

@@LAactor thank you, there's a trick I considered doing that doesn't involve drilling. There is a video of it here on KZbin. Something along the lines of using a nut as a spacer. Forget the details. End result is the 02 sensor remains wired in but readings are too low to throw a code.

[@christophervanzetta]

@@plutosforest Using spacer’s for the O2 sensor should help.

[@davidelizabeth4933]

Thanks for the info, Peter! ❤❤❤

[@robertblacksmith4355]

We got rid of Emission testing in 2014 older cars have the Cats taken out !

[@mmarte1622]

So to solve that problem all those parts needs to be changed? Or would the AFS suffice?

[@LAactor]

It would depend on which part is malfunctioning or broken. I personally feel that oxygen sensors do not need replacing on Toyotas and if they do turn out to be bad, specifically from a code or waveform graph, then to replace them. But someone else said they changed the oxygen sensor when they had a cat code and it helped them. So it really depends on the car. And driver. Your Camry might be one thing and another guy's Camry might be another.

[@miriamvivo4279]

Ohm test for resistance. Check out you tube videos and save mucho denero

[@johnle6754]

Where is your shop located at?

[@chevinbarghest8453]

Genuine OEM Denso O2 sensor for Toyota Camry 2017, is $44.42 at Amazon ....free shipping....(just an example)

[@christophervanzetta]

They are probably knock offs as most are from ebay and amazon

[@SteveMaGuff]

Feel free to show us how to replace it. It looks like a lot of work

[@FleaMarketJohn]

👍

[@rondhole]

Often only the catalytic converter and exhaust gaskets need replacement. if there is no O2 sensor codes, no need to replace them

[@gary8017]

the lighting was better at the other shop

[@LAactor]

I think he took a few days off of videoing to test lighting and ISO/shutter speed settings. I asked him to look at that because the autofocus was having trouble with the excess light so I suggested he pull the aperture down and play with it. It's a work in progress to find the correct combination again.

[@cartap22]

Yeeeeeee

[@TheRealHungryJoe]

@Account NumberEight apparently.

[@cartap22]

No I’m learning how to type.

[@slipnslide83]

UMMMMMMMMMMMMMMMMM'

[@HouseCallAutoRepair]

And if you don't address the cause of failure, the new one will fail too.