How to change o2 sensor

[Bad Luck]

The problem with Denso's FindMyPart is it, well, doesnt find your part. It will list every O2/AF sensor used and/or compatible with our vehicle, but it won't tell you what yours came with, and it really varied between years/trim/emissions. I highly recommend you double and triple check the part numbers with other websites before purchasing, I ended up having to order several until I received the right ones initally because of FindMyPart. Hell one of the ones Denso told me would fit didn't even have the right plug. It was a year ago but if I recall correctly measuring how long they are really helped find the right ones

I though it was really easy to use. All you need to know is your engine and if you have federal (one cat) or california (two cats) emissions and how long of a harness you need. It shows you the plug in the details along with the harness length.

 

[PNW yota]

My stud were completely rusted, $100 at the local muffler shop and they replaced the tailpipe section, welded in a replacement sensor bracket, and installed the new sensor (I had already bought the sensor). Sharing in case someone run into major issues removing the bolts


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I think I’m going this route. Comparing the stud lengths from front to rear I’m not even sure what’s left on those. They’re at least 1/2 inch shorter than the front studs.

 

[PNW yota]

Wait... you mean a proper shop did all of that for $100? That's less than the price of the sensor.

I know the part is almost $200! I think i would have to replace both at the same time. So with that said i've already spent $400 and the truck aint even on the lift yet!

I snagged both off Amazon (sold by Amazon not third party) and they appear to be legit denzo. About $50 each.

 

[giguchan]

Thanks for the reply..
Sounds like you got it all sorted out. I'm going to have to re evaluate my exhaust system. It's rusty under there..

 

[Chitwood]

I snagged both off Amazon (sold by Amazon not third party) and they appear to be legit denzo. About $50 each.

From what I can tell, the front two sensors are the same part (234-9047). The downstream sensors seem to have different part numbers depending on which side they're on (234-4804, Bank 2 or left; 234-4805 Bank 1 or right).

Amazon does sell the Denso sensors but the forward sensors are more than double ($102.90 vs $46.88). Why the price difference?

 

[mtbtim]

From what I can tell, the front two sensors are the same part (234-9047). The downstream sensors seem to have different part numbers depending on which side they're on (234-4804, Bank 2 or left; 234-4805 Bank 1 or right).

Amazon does sell the Denso sensors but the forward sensors are more than double ($102.90 vs $46.88). Why the price difference?

The newer 3rd Gens have an upstream air/fuel sensor rather than an O2 sensor. That might be the reason for the difference in price you're seeing.

 

[Bad Luck]

From what I can tell, the front two sensors are the same part (234-9047). The downstream sensors seem to have different part numbers depending on which side they're on (234-4804, Bank 2 or left; 234-4805 Bank 1 or right).

Amazon does sell the Denso sensors but the forward sensors are more than double ($102.90 vs $46.88). Why the price difference?

Are you in the right section? 3rd gen 4Runners only have 1 bank of oxygen sensors

 

[Romeo1]

Make sure you get the right one. There’s a really good video on YouTube showing a Toyota mini van that had the wrong sensor up front after getting passed around a bunch of shops by an owner who didn’t know better. It wouldn’t start the OBD monitors because of it.

 

[adder70]

Confirming V6 locations

I got ambiguous info from my general shop who said that the check engine was related to an O2 sensor, but that it was rusted on and I needed to go to an exhaust shop to have a new mount welded on. I delayed and left the car mostly parked (Wife and I both work from home so no much need to drive it.) and now the general shop only said the notes said "cat con" so can't really tell if front or rear, and exhaust shop couldn't remember off hand if it was before, after or ON the cat con. (If on the cat-con, welding doesn't go so well, i.e. new cat-con).

I'd like to know beforehand if the sensors are before and after, or if either is on the cat con for a V6 limited 2000 4Runner.

Amazingly, many pictures online but none that I could find are clearly V6 that also show locations to ensure neither is on the cat-con.

 

[Bad Luck]

I got ambiguous info from my general shop who said that the check engine was related to an O2 sensor, but that it was rusted on and I needed to go to an exhaust shop to have a new mount welded on. I delayed and left the car mostly parked (Wife and I both work from home so no much need to drive it.) and now the general shop only said the notes said "cat con" so can't really tell if front or rear, and exhaust shop couldn't remember off hand if it was before, after or ON the cat con. (If on the cat-con, welding doesn't go so well, i.e. new cat-con).

I'd like to know beforehand if the sensors are before and after, or if either is on the cat con for a V6 limited 2000 4Runner.

Amazingly, many pictures online but none that I could find are clearly V6 that also show locations to ensure neither is on the cat-con.

There is an oxygen sensor before and after the catalytic converter(s). If you know what the code is we can tell you which sensor it is. If you know whether you are federal emissions (1 cat) or California emissions (2 cats) and 2wd/4wd we can probably even tell you the sensor part number.

 

[mtbtim]

I got ambiguous info from my general shop who said that the check engine was related to an O2 sensor, but that it was rusted on and I needed to go to an exhaust shop to have a new mount welded on. I delayed and left the car mostly parked (Wife and I both work from home so no much need to drive it.) and now the general shop only said the notes said "cat con" so can't really tell if front or rear, and exhaust shop couldn't remember off hand if it was before, after or ON the cat con. (If on the cat-con, welding doesn't go so well, i.e. new cat-con).

I'd like to know beforehand if the sensors are before and after, or if either is on the cat con for a V6 limited 2000 4Runner.

Amazingly, many pictures online but none that I could find are clearly V6 that also show locations to ensure neither is on the cat-con.

Do yourself a favor and go on Amazon and buy yourself an affordable OBD II reader so you can read and clear CEL codes. Like [MENTION=319302]Bad Luck[/MENTION] said, you can tell by the code if it's the upstream or downstream sensor.

There is an emissions sticker under your hood which will tell if your rig is using Federal Emissions or California emissions. Once you figure that out and you figure out which sensor you need, you can use this sight to get the correct one. ERROR: The request could not be satisfied

You have to search carefully on that Denso site and make sure you are finding the right part numbers. It's based on whether your rig is Federal or California emissions, whether it's 2wd or 4wd and whether you have an automatic or manual transmission.

The suggestion of going to a muffler shop is a good one. They can weld on new O2 sensor bungs for you if yours are too far gone from corrosion.

This video will help you out at some level, but dealing with the rusted nuts and studs will be your biggest battle. You might have to cut them off.

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