O2 Sensors is it Upstream or Downstream?

[@1AAuto]

√ *Watch the Video* √ *Buy The Part at 1A Auto* 1aau.to/m/Visit-1AAuto √ *Do it Yourself* √ *Save Money*

[@georgesimonsen8483]

Buy them

[@georgesimonsen8483]

I'm done

[@MrBangla11]

Now what happens if u interchange the upstream to the downstream and the downstream to the upstream the actual sensors?

[@Armageddon-qo4wy]

What if you have a BMW 4 Cylinder with 2 cat converters and 4 sensors? 2 upstream and 2 at the rear of the cat converters? How do I know which is bank 1, sensor 1?

[@kikibarrios1231]

My 1997 F-150 was OBD scanned after my gas cap broke in half, and when I put in another one, same exact cap, except functional, I was driving with a bad one before and I got a check engine light. OBD said it was the O2 sensor, is the cap faulty, or sensor bad? Autozone told me the cap can cause that code to appear and I dunno now.0

[@TRUNOS]

This is one of the only videos I can find where someone actually explains upstream and downstream positioning and what they mean. Thank you

[@josiahmoss3240]

Went and bought 2 O2 sensors; one of them cost a few bucks more ; when i got home and opened each box( different parts number) the sensors were exactly alike, only difference was the length of the wiring;

[@drosser8461]

Excellent question which has caused much confusion - unfortunately, you spent the entire video clarifying a different issue. Okay, so I have purchased an upstream and a downstream sensor, taken them out of their boxes, then am called away for an urgent phone call. On return, I forget which came out of which box. How does your answer help? You have described the function of the sensors well - but your question was 'how can you tell the difference?'. It does not need a video to demonstrate their location on the vehicle. Surely there should be an identifying part number stamped on the body of the unit or a tab on the cable like any other part. Can you clarify how to identify the sensors without the questionable on car comparison (bearing in mind that aftermarket units may look different anyway0

[@LA_Rider_]

if you are replacing the O2 Sensors, your OBD reader will tell you which one you need. Which bank, 1 or 2, if not both. O2 sensors last around 100k-150k miles max. Not a bad idea to replace both if one goes out. They usually run $20-$40 or OEM parts. Never use aftermarket for sensors. They often do not communicate with the vehicles ECM/PCM processor and you still get codes after you replace with aftermarket

[@tagminda4565]

Agree. It took the whole video just for location. 1 minute should be more than enough to tell which one is for such.

[@AusTxBill]

I have a different question.I have a 2006 Ford F150. I know from my dealer that the upstream and downstream oxygen sensors are two different part numbers. It shows part number 4L3Z-9G444-AA is the Exhaust Gas Oxygen sensor and part # XL3Z-9F472-AA is the HEGO Oxygen sensor. So I was looking to figure out which is upstream and which is downstream. I can't compare them to the ones on my pickup because a previous owner put in 4 of the same part number. I was hoping this video would tell me which one is upstream and which is downstream. Guess it's a trip back to the dealer.

[@idahogreen2885]

Oh fuck off nerd. Sticktoitivness counts. Dont blame the vid cuz you lost track

[@idahogreen2885]

Plus ones fatter than the other one, open yer eyes and shut yer mouth

[@xgtmg]

My upstream and downstream sensors have different connectors. I found out when the ones I bought off of eBay wouldn't plug in. The ad said upstream and downstream but I had two upstream sensors. Had to order some downstream sensors to finish the job.

[@shobud7561]

If the 02 sensors are different, how do you determine which one goes where ? Someone could have already put the incorrect one in the wrong place.

[@KC-vp7wn]

You are the first person to tell you how to determine O2 banks. Though it now makes sense to me that the bank of cylinders with the number 1 cylinder will be bank one not everyone will make that connection in their heads. Thank you for spelling that out to us! Now I can go and change out my bad bank 1 sensor 2 O2 sensor and have the right one changed out!

[@1AAuto]

+Kurt Cafini Thank you for the great reply. We love to empower our customers by showing you how-to perform your own auto repairs while installing our high quality auto parts. Have a great day! 1aauto.com

[@343ForwardUntoDawn]

Same! So happy 😊

[@Se2n67g9r]

Like all other videos it did not answer the question. It described the location of the sensor.thats all. But the answer is: any oxygen sensor can be either upstream or downstream. If you have one in a box or on the table and you dont know where it goes remember you can use it for either upstream or downstream.

[@yukiostrachan2048]

Thank you for helping me understand that my 4 cylinder engine only has Bank 1. This video helped me immensely.

[@fernandogalvao6718]

Excellent educational video. Thanks for explaining what banks are and which engines incorporate them.

[@wtfsnotaken]

I would have to agree I have a better understanding now of my VSC light and the bank codes

[@shiddy.]

FYI ... I found out today that accidentally leaving one of the hoses on the intake near the air filter disconnected after changing the air filter will throw the exact code for this bank1 sensor2 O2 sensor failure my torque app said the light was on for 'o2 sensor slow to respond' ... instantly fixed by fixing the disconnected hose on the side of the intake tube if you have this code for bank1 sensor 2, first check all of the hoses that attach to the intake before digging into this O2 sensor repair - especially if you've recently had the air filter out if writing this helps at least one person it's worth it

[@kccodex8931]

Lose the music, it's pointless and distracting.

[@Cougar1212]

This doesn't answer MY question. Are the sensing heads different? There's only one "O2 sensor" for my silverado on every parts online store I look. Is it just wire lengths that vary? If the plugs reach their harness, can I use the same part for up or downstream? Thanks.

[@alexchavez2550]

Perfect video guys, saved my a headache before my repair tomorrow

[@RyanandSaraDelling]

That is the cleanest looking '96 underbelly I've ever seen

[@Sean-John]

I was just thinking that 🤣

[@johnoneill8842]

Probably stared in a ton of other A1 Auto repair videos.

[@time2maked0hnutz54]

Camera tricks 😆

[@mrequi1]

No kidding, my 96 looks NOTHING like this

[@clintzimmermann5838]

There is no way that came from upstate NY

[@wisamabazly]

Best description ever..lots of great help.thank you ..best video.

[@1AAuto]

+wisamabazly Thank you for the great reply. We love to empower our customers by showing you how-to perform your own auto repairs while installing our high quality auto parts. Have a great day! 1aauto.com

[@mmlindsey8635]

EXCELLENT..EXPLANATION ABOUT O2SENSOR 👍

[@1AAuto]

+M&M LINDSEY Thanks for checking us out. 1aauto.com

[@millyonair9225]

Excellent explanation! You're a GREAT communicator, bro!

[@uawsux]

Upstream downstream Left Bank right Bank sensor 1 sensor 2 front and rear left or right up or down I'm glad this thing isn't in a circle you explain the easy stuff let's get to the front and rear on a transverse mounted engine

[@lotus956]

Turn your engine on. Locate catalytic convertor by touching the ballooned portion of exhaust. It should melt your hand off. It has two wires fore and aft of it.

[@tylerseabook9423]

🤦‍♂️🤦‍♂️

[@MattAllen-c9d]

Good video little late watching this but just subscribed to your guys channel hope to see more amazing videos helped me out a ton as a young guy trying to become a mechanic one day very informative straight to the point but also very detailed great job keep making these videos !

[@davidharrell9902]

This explains everything so simply. Thanks for your time and I look forward to your other videos

[@bigkev6784]

Man VERY excellent video & VERY informative. Thank ypu

[@1AAuto]

+big kev Thanks for checking us out. 1aauto.com

[@corymollak2093]

You almost answered my question in fact when I think about it almost everyone almost answers my question. I got the different placements of the O2 sensors. My question is they're both installed just in the wrong based on electrical connection , but they both still plugged in(didn't force the connections just weren't notch out)do I have to worry about swapping them back. Ultimately, is there a fundamental design difference in each one...in other words is one specifically designed to catch the Upstream exhaust in one particularly designed catch the downstream or do they both function the same?

[@FSmithSE1]

VERY HELPFUL VIDEO REGARDING ID OF UPSTREAM & DOWNSTREAM O2 SENSORS.

[@1AAuto]

+SPARTAN SMITH Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@Dr2009king]

That was simple and straight to the point.

[@LamontGranquist]

What happens if you replace an upstream O2 sensor with a downstream O2 sensor accidentally? They serve a different function but how are they different and what goes wrong if you mix them up?

[@leabutler9542]

I did this by accident and the engine started misfiring

[@Baked26]

Look how clean that warehouse is, damn!

[@adrianruiz4904]

They obviously cleaned it leading up to the video

[@rogeliovmartinez]

thats why i love 1AAuto

[@matmanpromotions6457]

Thanks from down under. clear and concise tutorage.

[@dannypalmer7701]

Nice explaining everything i been wanting to know!

[@1AAuto]

+Danny Palmer Thanks for checking us out. Shop for high quality auto parts on 1AAuto.com: 1aau.to/m/Shop-1AAuto-c

[@jayg1078]

WOW! The best illustration of upstream and downstream and bank1 and bank2. Thank you, brother.

[@1AAuto]

+JAY G Thanks for the feedback and for watching!

[@Livinlivin836]

Bought my o2 sensors from here they’re a great product !

[@1AAuto]

+Israel Reyes Thank you for your order! We'd love to hear about your experience. Here's a link to leave us a review on Google: goo.gl/i5JFNY

[@sapoloc7115]

Good description, thank you always very helpful.

[@1AAuto]

+Sapo loc Thanks for checking us out! 1AAuto.com

[@rodger603]

I'm seeing three O2 sensors on my 2007 Ford Focus. I don't know if there's one underneath the car yet but the third one from the motor they cut it and I'm guessing that one went bad in the former owner did not replace it. I'm having a check engine O2 sensor light coming on

[@airon6864]

I changed out my upstream o2 and cleaned my MAF with CRC spray. No engine light: I just figured it was about time. It restored so much power but I didn’t change the cheaper one. I’m assuming that’s the down stream o2. Do you think it would restore even more power? I’m at 179k miles on my Camry se 2.5l and I like to stay ahead of things. At the same time I was losing power and once o cleaned the MAF and changed the most expensive o2 sensor it made a huge difference. Just wanted to know if the other o2 sensor would be worth changing too even tho I don’t have a light on

[@pepi8433]

hmm, i have service engine soon

[@joearanda86]

Thank you thank you for telling me what I needed to know I appreciate it and I love your videos

[@patriciawhite6429]

how do you know which one needs to be replaced? i have a 1996 dodge 2500 van and its sluggish on take off and dies when i reverse onto an incline with just the back end raised up. that is the only time it dies out and i am able to restart without moving it. great video thank you

[@jmo5592]

Very great information thank you for the help👍🏼

[@QueBall5235]

NOW this was helpful very detailed very specific information very helpful thank you 04 ford f150 fx4 5.4L v8

[@samuelmartinez1014]

Thank you guys, this video is so good, keep it up!

[@1AAuto]

+Samuel Martinez Thanks for checking us out! 1AAuto.com

[@MississippiTaiter]

Watch this video, but literally the only part I wanted to see was the O2 sensor it connected up to it and didn’t show that so it was kind of pointless in my opinion but props on the following of y’alls page

[@jimmyd33dz78]

you didn't show the tips when you mentioned upstream or downstream. You just held them up and said this is, and that is that. SEE and SAY.

[@1AAuto]

+James De Diemar Thanks for the feedback!

[@damygeebo]

@@1AAuto ...also, you didn't explain the visual difference between the tips of the upstream vs the downstream sensors.

[@miguelvargas6017]

You should do an installment video

[@hammer8809]

Depends on the vehicle, v6 3.0 liter GM LFW have same sensor for pre and post cat.

[@brentcampbell3060]

Hello....how many o2 sensors are on a Ford Taurus 2007? Thank you for your time.

[@hayderali9385]

Thanks for your video.. Is it possible to clean both sensor as maintenance and work performance better...???

[@bekainjgia2910]

Thanks for your explanation, it is very helpful, but is there differences for instance in upstream sensor driver side or passenger side?

[@fehronation8310]

Thanks for the knowledge 👌🏽👌🏽

[@1AAuto]

+Fehro Nation Thanks for checking us out! 1AAuto.com

[@halmiller5487]

He didn't show very well what the front and/or rear sensor looked like from each while under the car. I think the upstream senor had holes in it while the downstream one was solid but I not sure. He didn't make it clear which one was which. When the sensors were clearly shown, it wasn't stated which one was which.

[@hanknmosul]

If you look closely at the video, the downstream sensor body is thicker than the upstream sensor, and the replacement sensors had the same body type (downstream was thicker). I'm thinking that visual comparison was the determining factor when deciding which sensor went where.

[@redelrojas2098]

Good job. I have a 2003 Hyundai Santa Fe V6 2.7L. Could you tell me where is Bank 2 - Sensor 2 and what are other names that it has?

[@pedrocordova9317]

Hey, so i ordered both Bank 1 and Bank 2 O2 sensor downstream, for my 2007 Express 3500. Pretty much the same part. But the difference is that when i took one of the down stream O2 sensors off, it looked like your Upstream sensor. You think someone messed up and put the wrong one on? or is it good? lol. thank you.

[@1AAuto]

+Pedro Cordova It's possible! We recommend having a mechanic take a look. Thanks for checking us out!

[@Bfocus23]

Great value thanks

[@weeronnie100]

Yep best and easiest to understand well done mate 👍

[@mimusic1853]

Right to the point. Thank you A++

[@JinilThilakan]

Which sensor issue cause problems to the car? One Mechanic told me one of my O2 sensor needs a change and its fine to drive with it and the problem will only arise if the other sensor goes wrong. Which would it be?

[@sheldonharbour3596]

So you can use the upstream and downstream O2 sensors interchangably and there wouldn't be any issue?

[@damygeebo]

A1 sent me a "downstream" sensor that visually looks identical to my upstream sensor. How do you visually tell the difference between the two sensors when they are not on the vehicle?

[@SerenoOunce]

Physically and functionally they are identical. Only difference is what the internal heater's resistance is calibrated for (6Ω - 16Ω). This is why even for universal sensors there are multiple SKU's. Generally the downstream will have a lower resistance than upstream, and likely why they are more prone to failure.

[@race-all]

@@SerenoOunce Finally, a good way to ID up & downstream is the resistance. I was about to give up looking for some real info on this. Thanks much.

[@dilippatel3268]

excellent video

[@jonboatmorava9115]

Which one will actually work for my truck? So far I have bought several sets from several places, maybe here also I'm not sure, and they all have been rejected by my truck. Why is this? I've bought almost every brand and type that the cost isn't outrageous. So do some vehicles have to have certain brands ? My 2000 gmc Sierra 1500 2wd 5.3 has rejected everything so far. Next is some that cost over 200 for the set.

[@wpatters1229]

One thing I have seen is the color of the plastic connector. Match those and you should be good. On a chevy one is white with a blue ring and the other is totally blue.

[@1AAuto]

+William Patterson Thanks for the feedback!

[@JesseLockeHere2Do]

Thank you!

[@donaldbiggs9391]

if the plug fits and the wire is long enough it is the right sensor no matter which one your replacing Is this what I am to assume?

[@DenKle-mw8iv]

When it comes to Bank 1 Upstream/Downstream, assuming the plug-in sockets to the harness are the same, the only real difference is the length. You could technically use 2 downstream O2 sensors as its the Harness socket that determines which job is which. Just don't put an O2 sensor on the downstream of the Cat and plug in the connector into the Upstream harness socket.

[@MariaGonzalez-ei1pv]

My question is on the 2:30 mark which sensor is the heater sensor?

[@androyd3283]

This was no help, the guy who stole my catalytic converter ripped the wiring and the sensors went with the CAT. Now I have to re wire and get new sensors but cannot compare to the existing.

[@ceej5714]

Im having issues with ordering the right parts for a 2012 Dodge Journey RT AWD. Mopar website is not clear on which sensor goes to which bank. Could you help please?

[@malikking8953]

Hey I have a 2007 Cadillac Escalade esv The check engine light came on in the cold was (P0050, P0154, P0155) Bank 2 sensor 1. I would like to know which sensor I have to get and if it upstream/downstreamI. Also please let me know which side of the truck is the sensor located. It would be nice if I can get a link for the sensor

[@jello-va7622]

Thanks very helpful

[@diversity2739]

thanks

[@itsjustnotlikethat]

can one identify the difference between the 2 if they were on a table? which one is the downstream?

[@AJ2MONEYGANG]

Good morning I have a question what is the difference between Jeep Liberty 2004 sensor like how to put it on or fix it

[@erik_ayala17]

Would both sensors get the same reading for ohms?

[@viper8177]

On a flat four how do you know whether it is the upstream or downstream that needs replacing if the fault codes you are getting just say bank 1 because this could mean either? Do you have to buy both parts and see which fixes the problem or do many cars today have the same O2 sensor for both upstream and downstream so this wont be a problem to do the trial and error and not spend twice as much?

[@1AAuto]

+ImperialJohn Thank you for checking us out. On the flat four, it will provide bank 1, and then sensor 1 or 2. If you receive sensor 1 this indicates the upstream, while sensor 2 means downstream. 1aauto.com

[@HeavenReservation]

thanks for the video, do you have a sensor 2 bank 2 for a 2019 Zo6 corvette?

[@deanjagger1190]

I have a 2014 town and country van, low millage on the engine, 120,345 miles. I comp. says I have to replace the C C. Expensive job, so I was told it might just be the sensors. Is there for on my van, I might replace them all? 2 up stream, 2 down stream.

[@speeduh-de2pz]

What if my downstream sensor needs to be replaced and I only have a downstream sensor available with me? Can I still use the upstream to replace the downstream sensor? And does the negative battery need to be disconnected when doing this? Thanks

[@ezye4567]

Hi , my catalytic converter is stolen with upstream sensor then I installed straight pipe but the engine light is on and the fuel consumption is very bad . Does installing upstream sensors into straight pipe will solve the problem? Thank you

[@gbengaakindele1851]

Hi, my car is a 1997 Toyota Camry with V6 engine (1mz-fe). I noticed some petrol leakage on the bank 2 cylinder. Meanwhile, the car is consuming gas more than expectation. I later realized that bank 2 oxygen sensor is bad and I replaced it. My question is that, while the bank 2 oxygen sensor was bad, could it be that the ECM is relying only on bank 1 oxygen sensor. Do both sensor have to send different signals to the ECM? Why is bank 1 not having similar problem? How do bank 1, bank 2 and the ECM work together?

[@ShadowManV3]

you can tell he is an actually mechanic by his hands lol

[@mikestevenson1318]

Good video .Thanks !

[@bigboytoyz541]

Some jeep 4.0 have split exhaust manifold having 2 banks

[@dannymcneal]

Very helpful!! Thanks!

[@1AAuto]

+Danny McNeal Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@omarruiz1333]

Are the rings that come with it just washers and serve a purpose?

[@skr3wb4llsr40]

What if all 4 sensors look identical. I purchase new ones, both Up & Downstream and the new ones look like yours in the video, the old ones i took out are all identical. Any help with that?

[@tanveerplaha5506]

On my 2007 Mazda3, check engine light is on and after scanning I got a code saying bad air fuel ratio sensor. How'd you know if the upstream sensor needs to be replaced or downstream?

[@liveandletlive2894]

Upstream

[@stevee5044]

wow excellent thank u

[@1AAuto]

+Steve E Thank you for your positive feedback! We are happy we could help.

[@Cdswjp]

Are primary o2 sensors the same as saying Upstream o2 sensors?

[@tmoneyscsu]

Yes

[@jamesadame6189]

I have a 96 Jeep Grand Cherokee. Are the 02 sensors the same as a 96 Jeep Cherokee?

[@ohioyodertoter6827]

Well described 🙏👌

[@unkhammunankh7252]

Are they interchangeable? I’ve ordered a few from Amazon that are listed as Upstream/Dowstream, but no markings on the product itself and all look the identical, unlike the ones I pulled from my vehicle. Anybody care to provide insight?

[@darktoadone5068]

My problem with o2 sensors is the parts people, I have two upstream and two downstream I need to change for my 2013 GMC Sierra which is a 5.3 liter and they ended up selling me ones for a 6.2 liter, thank god I looked and noticed the difference before installing them and got my money back, so I get home and called AC Delco and the person on the phone was giving my three different part numbers even after I gave them my VIN! So I got fed up with them and then called GM customer service and the guy had no clue, he looked for 10 minutes and finally gave up and said we need to look into this in further detail, we will call you back around next Tuesday. SMH.

[@DTUFINOPhotography]

Does the brand of sensor matter? I have a 2010 FX35 with 175K miles on it and want to change my downstream as i have not changed them in 5 years!

[@lcs1603]

Need a little help please. I have bought a new 02 sensor pre cat for my vauxhall insignia 1.8 petrol. Everything is the same apart from the end that goes into my manifold they're totally different. The old one is the same as yours on the right and the new one os the same as the one on your left (in pictures)

[@rodleisam]

how many downstream o2 sensor does a kia optima 2013 LX has? Thank you

[@r6blackandyellow]

I'm working on my son's 2004 ford focus. I get a code bank 1 sensor "3". Is there a sensor 3 or wet does it say that?

[@jat-justamaturetech-philpj8285]

I have a 2000 wj jeep. My OBD2 say's im running rich po172, po175 Bank 1 and Bank 2, but you just said there are only one bank? Can you clarify??

[@sammec2282]

I have only 1 sensor in Kia cerato 2014, does that mean 1 sensor will work both upstream and downstream ? And why it shows I have 2 sensors in scanner when I have only 1 ? And the upstream works good but downstream stays still at 460v, pls help, thank you

[@Better_Call_Raul]

Are you sure that 4 cylinder do not have Bank two? Toyota Parts told me that 2004 Camry SE 2.4l 4 cylinder has 3 sensors. Bank 1 Sensor 1 Air Fuel Sensor, Bank 1 Sensor 2 O2 Sensor-- Upstream Sensor s. Bank 2 Sensor 1 O2 Sensor-- Downtream sensor

[@jennyholmes693]

Hey is this true for all vehicles or my 2014 kia soul....🤔🤔