Using O2 Sensor Data in Diagnostics

[@JA-rc4uy]

As a forme ASE certified automotive technician, this is the best simple explanation I have seen in a very long time.

[@JoseRamirez-yh2ll]

As the video randomly auto played on my phone, I agree

[@aaronw2522]

I agree!

[@wildthoughts6959]

This is the best VIDEO explaining O2 sensors behavior . So many videos on this subject on YT, however all have spaghetti shaped information, unclear and disorganized or vague . This one nailed it. Thumbs up man. You should be teaching classes.

[@dereksmith7781]

Just watched this video in the cab of a truck I’m diagnosing 😂 you’re a saint man thanks for the clear cut straight to the point Info

[@TristanRega]

no wasting time, straight to the point, love videos like this, thank you this was very helpful!!

[@smartmotives]

Very well explained, I come back here often to refresh my knowledge on this

[@ronemtae3468]

What a great great explanation it’s the first time I’ve actually seen a video that makes sense. Thank you so much.

[@FranciscoJavierOutdoors]

Thanks for the info man, diagnosing mine for sudden loss of power after a while of driving. Mine is the inline 6 engine, so only 1 o2 before and 1 o2 after. I thought it couldve been the cat, but the charts look like your top 2 o2 readings. They look perfect. Thanks for this info again

[@pallen807]

Love this video Straight to the point . Unlike others video that want to tell use all about their life story than 2min of the video u get nothing. Keep it up thanks

[@Deviantsoundz]

Such a nice and simple explanation, and finally, someone mentions that the graphs should look different between sensor 1(up and down constantly) and 2 (a steady reading).

[@Danilo111]

Excellent video, I already knew most of this but it was a good refresher

[@Pk3_Garage]

This was very helpful. Need to diagnose a P420 on a 07 Toyota Camry. I suspect the Oxygen sensor but need to verify that first.

[@johnmcminn9455]

Great info. It should fluctuate on the front sensor .01 to .09 But on the sensor after the cat Should be flat . I am using spacer extentions

[@eurotrash55]

You can further verify cat performance but checking the temp of the exhaust pipe before and after the cat. Exhaust temp after the cat should be much cooler on a properly working cat. If the temp didn't change much, the cat definitely isn't doing it's job. That's a second test for confirmation.

[@1982mattd]

Love the video dude! Explaining the difference of a narrow band that you're working on here I believe is important information to note you're NOT talking wideband! Im definitely a shade tree mech here so I'm no mechanic in that sense of schooling but im learning lambda a/f sensors! They definitely read differently! Great video for a narrow band buddy! Not talking shit bro just it's good to share that info I think

[@KantusKid]

Concise explanation even if I still can't wrap my heads around it. It at least points me in the right direction.

[@MustangGuru]

Modern cars, the wide band O2 is before the CAT. Narrow band is after the CAT

[@carlosabreuv]

Very good video, short and to the point. Thanks Hunter!!

[@deanlhouston]

First question, In your video, was the vehicle engine idling or did you have it up at some specific RPM? I notice my post-cat sensor readings look flat during idle but sometimes in the .3mV range, sometimes in the .7 or .8 mV range. But when highway driving (~2200 RPM), it's switching up and down making me think the cat is bad. Is that normal for the O2 readings to behave differently in those two regimes? Second question, how can you test if the O2 sensor itself is working fine and not fooling you into thinking the cat isn't working correctly? I know the O2 sensor is pretty cheap compared with the cats, so guess I can go ahead and swap them out and see if problem remains, but is there a specific test you can perform on the O2 sensor to know if it's the problem instead of the cat? Thanks!

[@DM-mm7rs]

Same here. I would like to know exactly if he was at a certain rpm or idle.

[@Lpzn-us8iq]

Did you ever find out what the issue was?

[@jerrypeal653]

Good explanation. I use the O2 all the time .

[@Ikaruszaki]

Short and informative. Nice!

[@joshuastyron4418]

Great video. Very well explained

[@SilveradoUSA1]

Excellent video 👏👊

[@TwoHemiViewer]

That was articulated very well. Well done.

[@duckhunter8203]

Top explanation my friend many thanks👍🏻👍🏻

[@gustavocervantes5435]

Thank you for sharing your experience!! Great video👍

[@SEBAS31077]

great video simple and easy to understand

[@tonyn7141]

Thank you so much. Outstanding explanation.

[@otopere7331]

Beautiful job, simple and easy 👌

[@spencerlee9974]

awesome explanation thankyou

[@luisr2320]

Thank you for the information great video,

[@larrygibbons6489]

Excellent Instructional Video !!!

[@zimmbaboo6256]

Great video 👍

[@BigBriAutomotive]

Great explanation thanks

[@aldoladrondeguevara7259]

Gave you a thumbs up good simple video where I didn't have to stop my life and watch a 30min vid

[@mikecotton460]

Very clear and concise, thanks.

[@MrBerniebling]

Outstanding content, thank you.

[@PedroBarbosa-qh6hy]

Awesome explanation ! Thank you

[@markjohnson8162]

Great video and we’ll explained I have a psa citreon c4 1.2 eb pure tech reading downstream oxygen sensor reading too high watching that video tells me it’s the catylitic converter

[@6romansoldier]

Great vid, right to the point.

[@chrishedlund3196]

Very helpful. Thank you.

[@omar-mz7qy]

Great video !!!

[@DS-ss7vl]

Excellent. Thank you.

[@streetchrisg]

Great Video! My bank 2 sensor doesn't move from 1.25V. Have a p0158 code 02 circuit high voltage. I'm leaning towards a clogged catalytic converter even though I don't have a p0420 code. I may have a bad ground with a reading of 23 ohms on the ground wire.

[@neodiy]

How is the O2 sensor reading between idle vs while driving?

[@jerryt8116]

How do you know if catalytic converter is bad or 02 sensor?

[@dougmorris9107]

this was fantastic. thank you!

[@W0WHERMY]

I am trying to figure out if my B1S1 is bad or if cat is having issues or if something else is wrong. How do I know if the sensor itself is bad? It wouldn't go up and down as much or at all? When my car was idle, my muffler was rattling from the inside and got a P0420 code for low cat efficiency. Mentionned it to my mechanic and he had a look he said baffle seems broken so he replaced my muffler but he was not sure yet why the code and it seemed unlikely that it was caused by the muffler. After muffler replaced, the code eventually came back ( it has been coming and going). And when i rev low (kind of using the torque of the car to speed up) the exhaust gets really loud, kind of sounding like those cheap honda civic diy race cars. Its not super consistent but fairly easy to reproduce. I am going to do more troubleshooting afterwork, but if you have any ideas, let me know. Thanks!

[@smorrow0816]

How would you know if you had a bad rear o2 sensor not doing it’s job or if the cat is at fault not doing it’s job?

[@mahasish]

Good question. Hope somebody who knows the answer can reply.

[@nordicpride9708]

Perform a propane test. Scanner danner discusses this in several videos and in his book 👍🏻

[@99tahoelt]

In this example did the Bank 2 O2 sensor throw a DTC. Chasing a P0300 on my 07 escalade and I'm thinking of replacing the O2 sensors but I have no O2 codes pending or current.

[@GripFreak]

Scan tools don't identify faulty or bad components (parts). TEST don't guess. Best wishes!

[@jeremystice5694]

Awesome video

[@Coletrain0128]

Could you explain how to know if the o2 sensor is bad? Great video thanks!

[@and45r31]

best video

[@sumatrican5990]

I’m getting a stft of 99.2 on both banks downstream(stft b1+2,s-2…..99.2 steady) on my ford 4.6 2v 300k miles. Getting rough idle and power loss

[@raythomas4687]

That is as clear as a bell. Thanks

[@billmonroe8826]

Well explained!

[@brucelee9891]

Great Video. Thanks! Quick question: , if Cat is plugged at 3:00, why it(O2S22) fluctuates? Thanks.

[@garageassembled4701]

Your GOOD sensor 2 example and BAD sensor 2 example is the complete opposite as to what I have going on. Possible someone swapped plug connections on my car. They plug into the same area on car.

[@cacus2344]

how would the 1st O2 sensor readings be like when there is a vacuum leak near the intake manifold and while idle? should they stuck around 0.02v or oscillate around low values ? (Thanks for the video!)

[@randybrown6449]

I have a 0420,0430 codes on my 2014 Infiniti QX80 and I was using my Autel Maxicom 808 trying to diagnos if I need a catalytic or 0/2 sensors my air fuel volts were the same on each O/2 sensors bank 1 /2 was 1.2 and Bank 2 /2 was the same.And Bank 1/1 and 1/2 was the same .28 what can I look at next to find the right readings if those are not it

[@mr.hammer7080]

Good video

[@fuzzyfish80549]

At 1:20 you say we should see switching multiple times per second. But the graph is switching much slower than that, about 2 seconds for a full up and down. Yet you say it looks like those sensors are normal. I have to say it sounds contradictory. Could you please clear that up for me?

[@NoferTrunions]

The Bad Cat signal period is different from the upstream. Shouldn't the downstream have the same period as the upstream? (How can the downstream hold steady for a while and then dip? What is the process?

[@hectorsanchez1960]

I have a Ford expedition 2002, V8 5.4L I replaced a pipe under the intake manifold, a heater hose connected to the water pump, change new intake, replace spark plugs, coil packs, O2 sensors Now I have 2 codes p1152 and p1132 took it to get it diagnosed. I need to replace both front oxygen sensor first and erase the code. Run car until code turn off if the code comes on again I’ll need to bring it to dealer and replace computer.

[@wvjeepguy8178]

2012 Jeep Wrangler- I had a fault for bank 2 sensor 2, so with 130k miles on the Jeep, I replaced all 4 sensors. I am still getting the same p0158 fault code as before, so I hooked up my scanner and the bank 2 sensor 2 is showing a steady 1.275 volts that never changes, regardless of engine rpm or fuel delivery while the others fluctuate as normal. I ran some Catacleaner through the Jeep as per the instructions on the bottle. I didn't expect a complete fix, but I wanted to see if it would at least open the cat up enough to show a change on the sensor data, which it did not accomplish. I'm pretty much stuck now and don't really have the money to replace the cat, especially if that's not the issue. Would a bad wire or corroded ground cause the voltage to stay at a constant voltage like this?

[@_UserUser_]

What I don't understand is, when the Toyota corolla 4afe manual says that you must measure 8 or more fluctuations in 10 seconds . Does this means that you must count how many times it goes to 1volt as 1 fluctuation, or should you count the up and downs as 2 fluctuations? I mean, does an up and down circle, means 1 fluctuation or two?

[@tombuckley3061]

2000 express 5.7. No check engine light. On a long pull hill o2 show good but engine stalls progressively worse as the van goes up the hill. New cats and air flow sensor. Like not getting gas. In use of scope what should I be looking at.

[@timothyyergens7125]

I have a 02chevy 5.3 I have fixed the exhaust manifold leaks and change all of the o2 sensors and catalytic converter on bank 1 because I keep getting p420 code. Not sure exactly what to do next

[@rickpena1423]

Dude you are awesome

[@jasonminato8203]

Question, so my o2 sensor is just staying at 0.02v at idle, it can jump to a max of 4.9 when i rev it, so the data it's sending is faulty, but my question is, are there other factors that can make it rub such low voltage on idle, this is the pre-cat o2 sensor.

[@hunterautomotive4842]

What vehicle is it on?

[@balky23]

Awesome video and straight to the point. My question is on bank one I’m getting s1 between .01 and .90 and s2 between .030 and .810 On bank 2 s1 is .065 and .885 and s2 between .065 and .715 I am at my wits end with trying to complete the catalyst monitor and I can’t smog the vehicle What do you believe the problem is, all your help is appreciated Thank you

[@jaxnaturals]

That tells you that you have bad cats. Thus the reason you cant complete the cat monitor. If the cats are working you would see a steady voltage reading on both secondary sensors.

[@calebyoung1579]

Likely a bad o2 man. Or exhaust leaks between o2 sensors.

[@darreldomenko4464]

I have an O2 sensor that is constant negative value. Slowly going between -.09ma to -.05ma. Would this be a bad O2 sensor?

[@skywind007]

Are there any scan tools that instead of showing you a bunch of graphs, numbers, and abbreviations, it tells you a more meaningful conclusion such as "O2 sensor bad, please replace"?

[@spencerkitchens9188]

Too many variables at play. Would be nice though.

[@canuckfixit7722]

On my scanner hooked up to a Honda Element, I get O2S B1S1 in mA and Lambda B1S1 in a unit-less value. How do I compare with readings like yours in mV?

[@jamesfaison9410]

2014 Hyundai Elantra 1.8L Consistent P0420 code While looking at Sensor 2 reading, while driving on the highway, the voltage does switch some down to 0.1 volts but at idle it stays at 0.7 - 0.75 volts Also, while driving at highway speeds, when I take my foot off the accelerator and let the vehicle coast, the voltage goes to 0.000 volts and stays there until I push the accelerator again. I'm unable to look at the upstream voltage. I'm using Blue Driver and it says the PID is unavailable I'd like to condemn the post cat O2 sensor but I don't think I have enough evidence.

[@briansturgill5905]

I have 1 downstream steady at 0.6 and one steady at 0.1. Does that mean the low one is bad. It sometimes goes up in voltage but rarely.

[@luismoral4464]

I have a issue with my 02 sensor 1 bank 1 in my Murano first replacement on it came out with a voltage of 2.4 to 2.8 so I got another one now this one is putting out 1.5 to 1.8 for what I can see I shouldn't be having any other issues but a bad sensor do you think I'm right both sensor I purchase from Amazon e and eBay we're around 60 dollars your knowledgeable opinion could crack this case pleas let me know Ifvyou think paying the 231 dollars at AutoZone will fix this issue

[@lifeisamazing9980]

Please help me, i used an ODB reader. The upper o2 is ok jumps up and down like in the video. The downstream stays almost straight but 100, 115 to 120.

[@miman3]

Dude I love you

[@crystrezerex2life]

Question concerning a 2005 Honda Accord 3.0.....v6.....my bank 1 sensor 1 is barely reading 0.04 mili Amps.....and bank 2 sensor 1 is reading the same thing!! Is this the reason why my fuel trim is off? Computer tripped a p0171 code .....lean condition.

[@josephearl7983]

My Forscan reading shows bank 1 sensor 1 reading in Current mA or Imped V. I don't have a reading in mV like your scan tool shows.I'm getting a P219A code, Lean bank 1, and the mA reading goes from 0.00 to -0.11, and the V reading is 1.02 to 1.01. Does this indicate a bad O2 sensor? Thanks!

[@chucksteak4054]

I thought stoichiometric readings only came from downstream o2? I have a sienna with pre cats, and the readings fluctuate but stay roughly the same number

[@turbot6592]

O2 sensor 1 doesn't look consistent. It could be lazy and on its way out

[@michaelolson571]

My O2 sensor on bank 1 is showing 0 volts, but I have no error codes (2009 Honda Accord). Not sure what to think.

[@Mr.G626]

thanks 👍

[@KINGRG1]

Can an O2 look normal percentage wise on a scanner but still be bad?

[@gr2262]

I have a 2000 tacoma v6. I recently had a p301 cyl 1 misfire and p0300 random misfire codes. Found a bad cyl 1 injector, replaced it and the code went away and check engine light disappeared. A few days later, I get a new check engine code for p0420 catalyst below threshold bank 1 (my scanner doesnt say which sensor just says bank 1). I get my obd2 scanner and check live data and at idle my upstream sensor reads from 0.00 to 900, fluctuating in between every second like you described and the downstream sensor is slowly fluctuating from 3.254 to 3.300. Not sure what to make of this but if I understand what you're explaining is that my B1S1 (upstream before cat) is working properly and the B1S2 (after cat) is not? Help would be greatly appreciated

[@zakt938]

Solid video

[@MrMaster2262]

I have a NOx absorber B2 fail when i did a monitor test with a code reader but i can't seem to find out what a NOx absorber B2 is... i take it the B2 is bank 2 and the NOx is an oxygen sensor but where is this... upstream or downstream. i have a Ford Focus 2009 1.6 TDCI any help would be highly appreciated 🙏

[@mafosa8519]

Can the reading be done on a standalone o-scope?

[@WV591]

wish somebody would do this on wideband O2 sensors.

[@gabrielturinici5220]

Good video keep on ! A small question, apologies if it has been answered: I thought that the average value of downstream O2 sensor should be around 0.45; or, in your case even for the one working well (S12) it seems that the average is about 0.7 instead of .45mV. Any clue of why this is so ?

[@Rusko1DUB]

the downostream must be 0.7-0.9, if it high voltage that means that the all remained oxygen are burned in catalyst and the downstram o2 sensor dont depistate oxygen in exhaust and show 0.7+, if it show less 0v - 0.6v then is to much unburned oxygen in exhaust and ecm thinks that the catalyst is not efficient or is cloged

[@shaharsigal6729]

Is it possible that the 2nd downstream O2 sensor also bad (and/or)? I probably would not condemn a CAT before testing the O2.

[@WillPower0231]

Would you say there is an issue if the Post Catalytic converter readings are pretty steady but very high? Both bank one and two are solid at 720ish MV…. Pre cat, O2 are showing regular like yours. But I am having severe lack of engine power.

[@theraysantos]

So how do you know if the downstream sensor is the problem or the cat is?

[@Lambros_Stefaneas]

nice video.

[@TheSpade83]

Have a 2003 explore 4.0 with bank 1 sensor 1 reading between 0.00 and 0.780. Similar with bank 2 sensor 1 and scan tool is reading lean condition on both with a rough idle. What’s your thought?

[@hassansmw5634]

Thank you. Great job very informative. one question. Can $50 scanners test o2 sensor voltages? specifically the innova 5210 which I'm trying to buy.

[@hunterautomotive4842]

It should be able to

[@ajj62283]

can you use these readings to find out if your o2 sensors are broken?

[@alexanderthagreat840]

My b1 s2 will go down to .200 then if you rev it it will hit up to .820 then fall back down to around .200. B1 s2 stft is at 99.2 percent. If you try to hammer on gas it will buck and jump but if you let off and accelerate slow it will stop.

[@hunterautomotive4842]

Sounds like it is running lean. I would not suspect a fuel delivery problem because it goes rich when you rev it. I would also not think o2 sensors because they seem to be responding. Maybe go after either vacuum leaks or maf sensor or something along those lines.

[@alexanderthagreat840]

Whole reason I started looking is it has no codes, but if you accelerate hard it’s starts bouncing back and forth on rpm and starts flashing the random misfire code. But if you let off it goes away. Light throttle driving is fine. I’ve tuned it up. Checked pcv. Couldn’t find any vacuum leaks. It only does it under load. So I was thinking cat 275* inlet temp and around 600* outlet temp but it seems working. But appreciate the info I’m just lost in the sauce looking for the last noodle. The no code thing sucks.

[@user-dh8ch7vn8l]

السلام عليكم. فيديو جيد. واريد ان أسأل هل الخط المسطح يعبر عن خلل في حساس الاوكسجين