Best automotive replacement oxygen sensors according to redditors

Another idea: try cleaning your air intake valve (spray some carb cleaner in there and clean with a cloth.). Kinda sounds like that valve might be sticking.

Another semi-cheap fix that could be related is your 02 sensors. You have to use something like this to remove https://www.amazon.com/dp/B01C4OB3XC?psc=1

Good call with the PB Blaster. Hit it with PB Blaster while its warm after a drive too, it will help it work down into the threads. The crow's foot wrench with a breaker bar always worked best for me.

Heat it up if you need to. And if that thing is really as rounded as it looks in the picture make sure you have a big ol' pair of vice grips and a mallet ready.

Edit: This is my favorite o2 sensor wrench because of the 1/2 inch drive option for a big breaker bar and the standard 3/8 drive if it is already loose.
http://www.amazon.com/Lisle-12390-Oxygen-Sensor-Wrench/dp/B001C6NE40/ref=sr_1_10?ie=UTF8&qid=1395785636&sr=8-10&keywords=o2+sensor+wrench

no, no performance loss, it's the same thing. I bought a $14 O2 removal bracket https://www.amazon.com/TEKTON-47749-8-Inch-Offset-Oxygen/dp/B00GMN4D1Q/ref=sr_1_4?ie=UTF8&qid=1501031562&sr=8-4&keywords=o2+sensor+socket

Mine was the upstream heated O2, bank 1. there are 4 sensors. 2 for each exhaust. one is upstream, one is downstream of the cat. I have a friend with a car lift so we just lifted it and went to work. Took an hour. Including rotating tires while it was up on the lift.

From Amazon: $3 Billion dollars ($3,132,018,433.00 to be precise) Bosch 15361 Oxygen Sensor

Edit: Down from a list price of $3,758,422,120.00 - Savings of $600 million

They're like $80 for one off Amazon. LINK

Also when mine failed I only got the Cat Inefficiency code. Replaced the sensor, ran my scan, reboot it, bam no codes after that.

I used identical sensors (now, in full disclosure, I used NGK sensors) in all four locations. My god be with you getting to some of the harness connectors.


This is precisely what I used, with 20k of smooth operation thus far: http://www.amazon.com/NGK-25044-Oxygen-Sensor-Packaging/dp/B001PNG622#

For sake of discussion I have a 1998 Discovery LE (north American).

While you're at it, drop in a set of 4hole injectors and replace the old single squirters.

Link for injectors I used: http://pages.ebay.com/motors/link/?nav=item.view&id=131681285103&alt=web

Is it an hx? If so it’s because the manuals have a wideband front o2, which the other cars don’t have. It will not work since it’s 5 wires vs 4.


https://www.amazon.com/NGK-24300-Oxygen-Sensor-Packaging/dp/B001PNAOQ6

I've heard these offset sockets get more leverage. They have that freeze spray (wart remover in a bigger automotive spray can. Soak with penetrating spray overnight?

Sorry, I've got you beat:
http://www.amazon.com/Bosch-15361-Oxygen-Sensor/dp/B000CF1WNM/ref=pd_sbs_jw_3

I just did the rear sensor on my 01 last weekend.

• I did the plug and play OEM-style one out of laziness. Zero problems with that, everything fit, getting under the carpet was easy after taking out the driver's seat + center console
  
  
• I used an O^2 sensor socket like this and it did its job fine
  
  
• I didn't have room to get a 1/2" drive socket in there, but used a 3/8" with an a random metal pipe as an ad hoc breaker bar and it came out NBD.
  
  The bad...
  
  
• The OEM-style cable has a pair of metal plates attached to some standoffs on the exhaust to keep it off of the exhaust and driveshaft... mine were rusted to shit on a California car. 10mm and 3/8" sockets spun with no effect (kinda visible on the first photo); 9mm sockets couldn't fit. I ended up breaking the rusty metal tab off and working out some BS with metal wire to hold the cable in place.
  
  I'd take a look at it before taking out the driver's seat and jacking the car up, possibly hit it with PB blaster beforehand and/or have an alternate plan :D

> I'm def the paranoid mom

I can tell :P

>Is this a DIY that someone not super knowledgeable on cars could do?

Mmm, probably. Trickiest bit is getting a tool that will get onto the sensor. If you're comfortable working lying down on the floor, you can probably do this without a lift or jackstands, but you'll need to take down the cover along the bottom of the car. It's held up by 3 12mm bolts and a ton of little plastic clips. Once that cover is off, it's just a matter of unclipping the sensor wiring and then unbolting the sensor. If you are standing at the front of the car looking down into the engine bay, you can see the top of the sensor if you look straight down the front of the engine, kind of in the middle or slightly to the passenger side of middle. If I remember right it's got a green wrap around the wire. I use one of these sockets and a flexible-head 3/8" ratchet to get them on and off, so you'll need to find something similar. Just remember your lefty-loosey and if it really doesn't want to come loose, don't force it as you don't want to rip the threads out of the cat pipe.

or you can just get a plug from Amazon and paint the top black

The top of the strut shaft should have something you can put some kind of wrench on. Sometimes it's a small hex section you can put a small 3/8 drive socket on. Sometimes it's a hex socket for a hex key/"Allen wrench".

What size is the nut? If it's 22mm (7/8"), you can sometimes use an oxygen sensor like this one https://amzn.com/B00390BS7C to turn the nut while holding the shaft from the top. Other times you can use an offset box wrench and hold the top while you tighten it.

http://smile.amazon.com/dp/B00390BS7C

> how big of a job am I looking at?

We need to make sure your wiring harness is not damaged/chewed by critters before making that call. Wiring repairs generally aren't too hard if you know how to properly cut and splice. The O2 sensor is only 4 wires. The sensor itself is only held in by the threads, so it's as easy as unscrewing the old one and screwing the new one back in. Sometimes these oxygen sensor adapters for your ratchet can help a lot for loosening the old one since it can be on there pretty tight.

You can get a bung welded in or find an exhaust shop that has them.

Its common for this gen civic to eat o2 sensors once in a while. if it ever pops up, usually replacing it works fine as long as its the only DTC you have. Bosch o2 sensor and the deep well o2 socket (prefer amazon one here and not this one from autozone as its weak and could strip your sensor)

After literally 20 seconds of searching on Amazon.

A new O2 sensor is a cheap and easy fix that you can knock out in a few minutes with a 17mm(?) wrench, a jack, and about 15mins. A new cat is indeed a whole other story. If you pick up one online be it OEM or 3rd party and take it to a muffler shop, it'd be quite a bit cheaper and just as good as going to the dealer.

I just did my own O2 sensor last week and my hi-flow cat is in the mail as I'm in a similar set of circumstances. Have fun.

oooh, just saw your model year.

pre1997 only has the upstream sensor, so its not an issue for us

you can buy pieces of straight pipe from Walker that have the threads for oxygen sensors in them and then weld them in place of the cats.


also, you could do it the redneck way if you want... all you have to do is remove your cats and bore them out, so take them off and use a hole-saw to drill out the filter media. its messy, but you retain O2 sensor functionality and the appearance of having cats. and this option doesnt involve welding if you dont know how.

So, O2 sensors do go out. That's possible. It's strange that it happened right after the other work.

The O2 sensors are part number 8 on this diagram. http://www.realoem.com/bmw/enUS/showparts?id=RE33-USA-08-2004-R53-Mini-Cooper_S&diagId=18_0475 There's 2 of them. One before the cat (the one on the left), called the "upstream O2 sensor" and one after the cat (the one on the right) called the "downstream O2 Sensor". The upstream one is important, because it controls how the engine behaves. The downstream one is only there to make sure the cat is working, so it can throw errors if you emissions are out of whack.

Also, be aware that shops have a high mark-up on parts. I don't know UK prices, so I'll do it with the US prices. So for example, the part lists for $215 USD. If you go to the shop, they'll charge you that much for the part. Parts are quite silly at times. According to Some smart people NGK makes the sensors, that they sell to Boche, which they sell to BMW. You can find the NGK version of the sensor for $99 Car parts are silly. The dealer gets a moderate amount of the markup on the part, but BMW takes a fair bit as well. Even if they give you the labor for free, they going to charge you 215 for the part, which they probably paid bmw 150-170 for.

That said, I have no problem with the dealership making money, I just want the process to be more transparent then it is. They need to make 200+/hr to cover all of their costs (insurance, tools, rent, labor, etc) It sounds like they are overall trying to treat you fairly.

So what to do depends on your situation and your handiness level. I'd start by checking to make sure the O2 sensors are actually plugged in since work was done recently. Perhaps in some of the work it got unplugged? The cables have a white jacket (that'll be covered in grime) that will run up from your exhaust up towards your computer, and plug in. Inspect both wires, make sure they don't appear to be damaged, and then make sure the connectors are on tight. I can probably find photos if you can't find the wires.

If you've got more time then money, replacing an O2 sensor isn't hard. You'll need to buy some tools, so your first few projects you'll only break even, but you'll have tools for next time your car needs some love. Or the car after your current mini... If you want to go down this route, I can provide info on how to do the swap.

Now the other half of the question of if it's related... If the O2 sensor itself went out, that happens, and that's not fishy. But the question is what error are you actually getting back from the computer. There's several different errors that can come back. One of the errors say "The sensor is reporting strange numbers! It's probably broken!" One says "The sensor isn't responding at all! It's unplugged or broken!" It depends on which one you're getting. The first one they can't cause at all really, the second could happen if they forgot to plug something in. If you're getting the disconnected error, you said they were working on your fan's wiring. It depends on what they did if it's possibly related to the fan wiring. If they were working on the fusebox wiring, or the ECU wiring, then they could have caused it.

In the US, most auto part stores will read the codes out of your car, and knowing the code number, I can tell you which sensor is broken, and which message it's saying. You can also buy a cheap code reader for $20, or a good one for about $60.

One choice you have is you can tell the dealership that you want your car back for a few days for some reason, and you'll bring it back. You can get the codes read, make sure it matches up, do a quick visual inspection, and know what's going on, and then decide if you want to take it back to the dealer or not for the rest of the repairs. Or you can take it to an independent shop as well. O2 sensors aren't hard to do, so any vaguely competent mechanic should do it correctly. It'll take them more time to figure out how to unplug the connector then anything else, probably.

The other choice you might go for is tell the "Sure, I know O2 sensors go out. If replacing the O2 sensor fixes it, sure, I'll pay for it. A part on my car wore out at the same time. Otherwise, if it's not the sensor, it's a wiring issue. And you just dug into the wiring of my fan, and you possible you broke some of the O2 sensor wiring, and I expect that fixed for free. And I shouldn't have to pay for the incorrectly replace O2 sensor." It kinda depends on which error is coming from the sensor though, and if the problem with your fan was in your fusebox and/or ECU.

I've never seen a carb'd vehicle with an O2 sensor bung. But the kit comes with one to weld on. They're really cheap. https://www.amazon.com/Vibrant-1194A-Standard-Oxygen-Sensor/dp/B00180870Q

yes sir



https://www.amazon.com/Vibrant-1194A-Standard-Oxygen-Sensor/dp/B00180870Q

Follow up: Would [this part] (https://www.amazon.com/Denso-234-9017-Fuel-Ratio-Sensor/dp/B00122EENE) work in an 04 civic? It's my beater car so I'm not worried about best quality parts, just need it street legal again.

Does it have a underhood label that says it is a California emissions vehicle?

I'm 99.99% positive it will. If this is the sensor in front of the cat, you need part # 234-9002 from denso
https://www.amazon.com/Denso-234-9002-Fuel-Ratio-Sensor/dp/B000C5YCYS

Update for anyone who might have searched for this:

I ordered this cheap OBD2 reader from ebay and it pulled up fault code P1135, which is a faulty air/intake sensor (Bank 1, Sensor 1).

The replacement sensor is about $95 on Amazon.

Here is the OEM upstream sensor you need: http://www.amazon.com/Denso-234-4099-Oxygen-Sensor/dp/B000C5WCN6/ref=sr_1_1?ie=UTF8&qid=1380741249&sr=8-1&keywords=2344099

You don't necessarily have to buy it off Amazon but they have the best price for it. Denso is Hondas OEM manufacturer. Make sure it is the Denso 234-4099 model number. It is what it came with. Also, for spark plugs and wires, use NGK. NGK ZFR5F-11. You should be able to go to an auto parts store and get those. It shouldn't cost more than $3 a piece and you need 4. Here are the spark plug wires: http://www.amazon.com/NGK-HE76-Premium-Spark-Plug/dp/B000IY8ODS/ref=sr_1_fkmr1_1?s=automotive&ie=UTF8&qid=1380741594&sr=1-1-fkmr1&ymm=1998%3Ahonda%3Acivic&keywords=1998+honda+civic+dx+spark+plug+wires

As for tools, you'll need a 7/8" offset o2 sensor socket and a breaker bar because it will be on tight! For the spark plugs, you'll need a 5/8 spark plug socket with a rubber piece or a magnet inside to grip the spark plug. the wires won't require tools but you'll need a bit of dielectric grease to prevent the elements from getting to the connections.

I recommend you use this spark plug socket. It's treated me really well and is very durable: http://www.amazon.com/GearWrench-80546-8-Inch-6-Inch-Swivel/dp/B0014ZVSVK/ref=sr_1_1?s=automotive&ie=UTF8&qid=1380741751&sr=1-1&keywords=spark+plug+tool Also, it won't hurt if you go and buy a 3/8" 6" extension for your 3/8" ratchet.

Also posted the wrong link I wanted this brand. TIA

https://www.amazon.com/Denso-234-4099-Oxygen-Sensor/dp/B000C5WCN6/ref=sr_1_2?crid=2Q4HDDP429DEO&keywords=denso+02+sensor+upstream&pd_rd_r=4631e148-4f9f-4c44-b01e-ae8388bba695&pd_rd_w=wwXoB&pd_rd_wg=FFNKP&pf_rd_p=db468e0a-f345-403c-baba-a1a898d543d1&pf_rd_r=6TE6891B00ERFDG8EP68&qid=1573752381&s=automotive&sprefix=denso+02+%2Cautomotive%2C203&sr=1-2&vehicle=1999-59-752-806---8-5-5752-1441-1-1---&vehicleName=1999+Honda+Civic

I'm seeing this one for 2004
Denso 234-9005 Oxygen Sensor https://www.amazon.com/dp/B000C5UFVM/ref=cm_sw_r_cp_apa_i_V5KVDbM13SB0J

Is that the right part? And yeah the sensor is just underneath the front of the car and is a simple ratchet and plug right?