Oh yea ASE certified tech here’s a question for you . What would make the rear o2 read rich on a 2 bank car and the upflow o2 is reading great the car uses lambda it’s a 17 bmw 750i on idle stays rich on acceleration it leans out and hovers around 500-800 cat temps are around 512 average . The rich reading on bank 2 sensor 2 has a slower response 700-850 you get a drop or 2 during brisk driving too 100 and goes all the way up to 1270 then off accel drop and goes back up to rich. No cel car run good will not clear o2 or cat used every car clean in the book even hooked up seafoam to a nitrous purge system to shoot straight into the intake and turbo . Replaced o2 sensor as well . Could I have a plugged or a cat going bad on bank 2 ??? Or do I have an injector issue dumping excess fuel? Bank 2 is always pulling fuel up to -25 and averages -14 bank 1 for comparison is around -5 to 0.0 front o2 in the 100-400 range rear o2 in the same range but also riches out from time to time any diag procedure will be appreciated!
@@nolimitrc1sounds like an injector issue either leaking or not spraying efficiently...monitor your fuel trim readings to verify rich conditions and also check for misfire data
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.
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
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
I agree with other comments this is the best training video for understanding scanner results for oxygen sensors and engine diagnostics. Information technology companies should write algorithms that bump the best (and succinct) educational vignettes to the top. A+ Thank you for sharing.
excellent! Important to consider the best cleaning methods..... and the main causes for lean and rich conditions. I just chased down several AIR leaks: intake and exhaust. One of the exhaust donut gaskets at the exhaust manifold had completely crumbled when I dismantled the connection, for example. SMOKE MACHINE is a simple and powerful tool everyone must have!
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).
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
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.
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!
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.
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.
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
What about the actual values of the rear O2 sensors. My 2004 Corvette is running lean, and the rears (while still relatively consistent) will hold at .130, then .5, then .7.... Roughly a minute or so at each stage
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?
What about an upstream o2 sensor that doesn't show any data at all on the graph,only the downstream is moving,is that a dead upstream o2 sensor?@@arturos.l.2248
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!
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.
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?
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?
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
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.
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.
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
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.
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?
I have question if I’m reading rich condition are that mean that my car is running lean since computer getting info to reduce fuel ? It’s kinda confusing for me. Thank you.
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
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 🙏
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.
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?
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!)
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
Oh yea ASE certified tech here’s a question for you . What would make the rear o2 read rich on a 2 bank car and the upflow o2 is reading great the car uses lambda it’s a 17 bmw 750i on idle stays rich on acceleration it leans out and hovers around 500-800 cat temps are around 512 average . The rich reading on bank 2 sensor 2 has a slower response 700-850 you get a drop or 2 during brisk driving too 100 and goes all the way up to 1270 then off accel drop and goes back up to rich. No cel car run good will not clear o2 or cat used every car clean in the book even hooked up seafoam to a nitrous purge system to shoot straight into the intake and turbo . Replaced o2 sensor as well . Could I have a plugged or a cat going bad on bank 2 ??? Or do I have an injector issue dumping excess fuel? Bank 2 is always pulling fuel up to -25 and averages -14 bank 1 for comparison is around -5 to 0.0 front o2 in the 100-400 range rear o2 in the same range but also riches out from time to time any diag procedure will be appreciated!
Hello I have a 2008 mustang have lean and reach condition at same time. New catalitycs new oxigen sensor but my upstream sensor don’t fluctuate always on 900 mv. New spark plugs new cables. help thank you.
Hello, question. My bank 1 sensor 1 stays constant at 2.3 V? Is the sensor bad? Fuel injectors are fully functional, maf sensor works. I have the turbo pressure sensor codes on my scanner also
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!
Hi, I have static values for the after CAT sensors, Both are showing 1,1 volt and I have random misfires. Both two sensors after CAT stopped at 1,1 volt. What could be the issue please?
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?
1:18 but its not switching multiple times a second tho, it switches about 0.5 times a second. this diagnostic tool updates information too slowly to capture multiple times a second signal? Hella o2 sensor guide shows it should switch up to 4 times a second.
As a forme ASE certified automotive technician, this is the best simple explanation I have seen in a very long time.
As the video randomly auto played on my phone, I agree
I agree!
Oh yea ASE certified tech here’s a question for you . What would make the rear o2 read rich on a 2 bank car and the upflow o2 is reading great the car uses lambda it’s a 17 bmw 750i on idle stays rich on acceleration it leans out and hovers around 500-800 cat temps are around 512 average . The rich reading on bank 2 sensor 2 has a slower response 700-850 you get a drop or 2 during brisk driving too 100 and goes all the way up to 1270 then off accel drop and goes back up to rich. No cel car run good will not clear o2 or cat used every car clean in the book even hooked up seafoam to a nitrous purge system to shoot straight into the intake and turbo . Replaced o2 sensor as well . Could I have a plugged or a cat going bad on bank 2 ??? Or do I have an injector issue dumping excess fuel? Bank 2 is always pulling fuel up to -25 and averages -14 bank 1 for comparison is around -5 to 0.0 front o2 in the 100-400 range rear o2 in the same range but also riches out from time to time any diag procedure will be appreciated!
@@nolimitrc1sounds like an injector issue either leaking or not spraying efficiently...monitor your fuel trim readings to verify rich conditions and also check for misfire data
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.
no wasting time, straight to the point, love videos like this, thank you this was very helpful!!
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
Very well explained, I come back here often to refresh my knowledge on this
What a great great explanation it’s the first time I’ve actually seen a video that makes sense. Thank you so much.
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
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
I agree with other comments this is the best training video for understanding scanner results for oxygen sensors and engine diagnostics. Information technology companies should write algorithms that bump the best (and succinct) educational vignettes to the top. A+ Thank you for sharing.
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
excellent! Important to consider the best cleaning methods..... and the main causes for lean and rich conditions. I just chased down several AIR leaks: intake and exhaust. One of the exhaust donut gaskets at the exhaust manifold had completely crumbled when I dismantled the connection, for example. SMOKE MACHINE is a simple and powerful tool everyone must have!
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).
Easy, to the point presentation. Thank you.
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.
Great video. Very well explained
Excellent video 👏👊
Excellent video, I already knew most of this but it was a good refresher
Concise explanation even if I still can't wrap my heads around it. It at least points me in the right direction.
Very good video, short and to the point. Thanks Hunter!!
Great video 👍
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
Top explanation my friend many thanks👍🏻👍🏻
Good explanation. I use the O2 all the time .
That was articulated very well. Well done.
Beautiful job, simple and easy 👌
Short and informative. Nice!
great video simple and easy to understand
Thank you for sharing your experience!! Great video👍
Thnaks for the video, very clear. What would the problem be when the readings are stuck 5V high?
awesome explanation thankyou
Great explanation!!! I really appreciate it
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.
Excellent video.
How is the O2 sensor reading between idle vs while driving?
Cool, cool. But how do you tell between a bad O2 reading from a bad sensor and a bad O2 sensor reading from a failed cat?
Thank you for the information great video,
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!
Same here. I would like to know exactly if he was at a certain rpm or idle.
Did you ever find out what the issue was?
I can tell you this was at idle. If he were cruising, the changes in the upstream graphs would be more frequent
Thank you so much. Outstanding explanation.
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.
Scan tools don't identify faulty or bad components (parts). TEST don't guess. Best wishes!
Excellent Instructional Video !!!
Great explanation thanks
Outstanding content, thank you.
How do you know if catalytic converter is bad or 02 sensor?
Very clear and concise, thanks.
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.
Awesome explanation ! Thank you
Good video
Great vid, right to the point.
What kind of readings do you see when you have a bad O2 sensor?
Awesome video
Great Video. Thanks! Quick question: , if Cat is plugged at 3:00, why it(O2S22) fluctuates? Thanks.
Very helpful. Thank you.
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
Excellent. Thank you.
What about the actual values of the rear O2 sensors. My 2004 Corvette is running lean, and the rears (while still relatively consistent) will hold at .130, then .5, then .7.... Roughly a minute or so at each stage
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?
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?
Good question. Hope somebody who knows the answer can reply.
Perform a propane test. Scanner danner discusses this in several videos and in his book 👍🏻
Typically the voltage readings would be stuck. If you Rev the engine to higher rpms, and the readings don't fluctuate at all, that's a bad o2 sensor
Typically the voltage readings would be stuck. If you Rev the engine to higher rpms, and the readings don't fluctuate at all, that's a bad o2 sensor
What about an upstream o2 sensor that doesn't show any data at all on the graph,only the downstream is moving,is that a dead upstream o2 sensor?@@arturos.l.2248
Gave you a thumbs up good simple video where I didn't have to stop my life and watch a 30min vid
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!
Dude I love you
Great video !!!
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.
Could you explain how to know if the o2 sensor is bad? Great video thanks!
Is this still relevant if the front O2 is a wideband/linear sensor?
No it’ll be different on a wideband
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?
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?
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
this was fantastic. thank you!
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
So how do you know if the downstream sensor is the problem or the cat is?
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.
السلام عليكم. فيديو جيد. واريد ان أسأل هل الخط المسطح يعبر عن خلل في حساس الاوكسجين
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.
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
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.
Is it possible that the 2nd downstream O2 sensor also bad (and/or)?
I probably would not condemn a CAT before testing the O2.
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?
I have question if I’m reading rich condition are that mean that my car is running lean since computer getting info to reduce fuel ? It’s kinda confusing for me.
Thank you.
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
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 🙏
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.
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?
Can an O2 look normal percentage wise on a scanner but still be bad?
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!)
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
Nice
Oh yea ASE certified tech here’s a question for you . What would make the rear o2 read rich on a 2 bank car and the upflow o2 is reading great the car uses lambda it’s a 17 bmw 750i on idle stays rich on acceleration it leans out and hovers around 500-800 cat temps are around 512 average . The rich reading on bank 2 sensor 2 has a slower response 700-850 you get a drop or 2 during brisk driving too 100 and goes all the way up to 1270 then off accel drop and goes back up to rich. No cel car run good will not clear o2 or cat used every car clean in the book even hooked up seafoam to a nitrous purge system to shoot straight into the intake and turbo . Replaced o2 sensor as well . Could I have a plugged or a cat going bad on bank 2 ??? Or do I have an injector issue dumping excess fuel? Bank 2 is always pulling fuel up to -25 and averages -14 bank 1 for comparison is around -5 to 0.0 front o2 in the 100-400 range rear o2 in the same range but also riches out from time to time any diag procedure will be appreciated!
Hello I have a 2008 mustang have lean and reach condition at same time. New catalitycs new oxigen sensor but my upstream sensor don’t fluctuate always on 900 mv. New spark plugs new cables. help thank you.
stoichiometric. . . A word I learned since messing with my o2 sensors
What if my downstream o2 sensor is at 1.275V and not moving, closed circuit ofc.
What if it intermittently follows the upstream and then goes back to normal.
Hello, question. My bank 1 sensor 1 stays constant at 2.3 V? Is the sensor bad? Fuel injectors are fully functional, maf sensor works. I have the turbo pressure sensor codes on my scanner also
That is as clear as a bell. Thanks
Well explained!
Hey I have the same exact scan device how do I get too that page
Ive a question. How can we tell if its the 02 sensors or the catalytic converter. Would we be looking for something different?
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!
Hi, I have static values for the after CAT sensors, Both are showing 1,1 volt and I have random misfires. Both two sensors after CAT stopped at 1,1 volt. What could be the issue please?
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?
1:18 but its not switching multiple times a second tho, it switches about 0.5 times a second. this diagnostic tool updates information too slowly to capture multiple times a second signal? Hella o2 sensor guide shows it should switch up to 4 times a second.