O2 Sensor - Bank 1 Sensor 1 - Replacement

[ChumpusRex]

It's a V6 - one wideband sensor for each half of the engine.

The post-cat sensors are present on all new cars. They are a legal requirement. They check if the catalytic converter is present and working properly. If it isn't, they put the engine/VSC light on, so that the car will fail an MOT. That's all they do, they don't do anything to help the engine run.

[agent_dess]

Ahh... a Threadlock! I didn't to push to hard thinking i might kill the screw threads

Ok i'll maybe try once more time.... Can someone please tell me how you manage to get a hammer into the confined space??

[johnatg]

You don't need a hammer - just a decent strong breaker bar (and a bit of strength!) and a socket - the sort specially designed for oxygen sensors with a slot in the side. If the sensor is not too tight an oe spanner will do.

[agent_dess]

I've got the lambda sensor tool.... my problem is that i don't have enough room to push/pull the sensor... I have even moved the fuse box to one side

[TigerFish]

If the lambda is cream crackered already, disconnect the plug and chop the wires off so you can use a ring spanner or standard socket. You only need to worry about the wires if you need to reuse it or are putting the new one back in :)

Sent from my Iphone using Lexus OC

[agent_dess]

Finally had the dash light with p1295 for bank 1 sensor 1... I'm on 83k but I've already given up on trying it myself so gonna hand it over to a local mechanic to deal with lol

[madasahatter]

The rear 2 i believe are a pain, wires go into car and seats to be removed. I stand corrected if any one knows different.

[james250]

Great write-up. You mentioned to put anti-seize grease on the thread of the new o2 sensor. Is it supposed to be anti-seize grease or loctite. I know on spark plugs I used anti-seize grease so assuming same should be on o2 sensors seeing as the general rule I think is that anything that you plan to remove should have anti-seize.

[ColinBarber]

anti-seize so you can remove them at a later date! Denso sensors comes with a small amount in the box.

[is200 Newbie]

The sensors (if genuine) come with a small tube of the stuff - as Colin has indicated above

[james250]

1 hour ago, is200 Newbie said:

The sensors (if genuine) come with a small tube of the stuff - as Colin has indicated above

Mine didn't seem to come with the tube. Just in a Denso box that has what appears to be Japanese writing. The sensor inside is in a vacuum sealed bag. Not sure if these are Genuine or Not. Maybe they are and made for the Japanese market where they maybe don't supply it with the tube? Below is a pic of it:

 

 

[is200 Newbie]

If there is a serial number on the wire (label) then I would contact Denso to check to see if the sensor is genuine as you don't want to do the job again - also, if new, they are supplied with a small tube of thread grease but you can use a small amount of copper ease on the threads. Its possible the last owner of this lost the tube of grease...

Careful with eBay things like this as there are a lot of fakes around, especially headlight bulbs (was featured on Fake Britain on the beeb last week)

If you have doubts about it being genuine I would replace the other sensor which is a 5 minute job with this one to prove it to save the hassle of removing it if duff? It doesn't look like its been used though as a used one would come out covered in light soot.

[james250]

2 hours ago, is200 Newbie said:

If there is a serial number on the wire (label) then I would contact Denso to check to see if the sensor is genuine as you don't want to do the job again - also, if new, they are supplied with a small tube of thread grease but you can use a small amount of copper ease on the threads. Its possible the last owner of this lost the tube of grease...

Careful with ebay things like this as there are a lot of fakes around, especially headlight bulbs (was featured on Fake Britain on the beeb last week)

If you have doubts about it being genuine I would replace the other sensor which is a 5 minute job with this one to prove it to save the hassle of removing it if duff? It doesn't look like its been used though as a used one would come out covered in light soot.

Will give that a try but I do think it might actually be genuine but made for japanese market. It's vacuum sealed and the actual sensor has denso serial numbers and stuff etched into just like OEM except the OEM one has Toyota name etched on it.

[james250]

@is200 Newbie and @normski2 I may be changing the sensors I got if it turns out they are bad. However, I am slightly confused regarding the part numbers. Upto 2008 Is250 has a OEM part number of 89467-30010. Now if you go to the densoautoparts website or rockauto website they give a denso equivalent part number 234-9051 which is what you purchased @is200 Newbie and for 2008 onwards they give denso part number 234-9048 and 234-9068. So if you actually go to most popular sites and auction sites you will actually find that no-one in Europe sells Denso part 234-9051. Even Denso Europe do not have this in their catalogue. 

It appears that to the European market, Denso Europe part numbers are completely different and here is my findings.

Note: the reference website is Denso Europe website which is: http://www.denso-am.co.uk/e-catalogue/ these are the people who companies like Euro Car Parts etc deal with to stock Denso parts.

According to Denso Europe website, the Denso Equivalent part number for 2005-2008 is DOX-0263. If you go into the specs of this as in screenshot below it matches the same spec as the one from the American Denso part number. The part number for 2008+ is DOX-0506 and according to the specs the main difference is the length of the cable.

If you look up the tech specs for the DOX-0263 it appears to fit the IS250 upto 2008. I went to Euro Cart Parts website and they have the Denso sensor advertised at over £329.99 each which is ridiculous. But it states it fits the OE number. So I spoke to Euro Cart Parts to see what the Denso Part number they have for that product is and they confirm that the Denso Part number is DOX-0263. 

The DOX-0263 is much more reasonably priced than the OEM toyota ones and you can get them only varying between £90 and £100 each. Not sure if anyone else has any experience with this. But there is not much info out there. And it appears the DOX range is a european product code with a EAN number. 

 

 

[james250]

Also further to my post above, I found the following youtube video which shows someone installing the DOX-0263 on IS250. It's not in English but the at 1minute in you can see the packaging that says DOX-0263

 

 

[Texas]

Great vid on how to change O2 sensor!!!!!!!!   Showed more of taking the Battery on and off than the sensor remove/refit 😀😀

[normski2]

I am left thinking there must be more space to get at the sensor on a LHD drive model.

There is no way I could have got my hand in there with just the Battery removed on the RHD vehicle.

@james250 You are quite right for my model (2010) it was the 9048 and 9068 types. Got mine via Rockauto in the USA. Interestingly the cables were indeed about 40-50mm different in length. I gave up with looking at the European sales outlets as there was conflicting data from various sources.

[james250]

14 hours ago, normski2 said:

I gave up with looking at the European sales outlets as there was conflicting data from various sources.

From all the research I have done, it seems that the European Denso sensors have different part numbers. I have no idea if the hardware itself is different. I checked with a few Denso suppliers and they all confirmed that DOX-0263 fits the Lexus IS250 upto 2008.

[is200 Newbie]

Don't know why they have made the selection so complicated ... the sensor does the same job in each bank, the two differing part numbers correspond to the correct sensor but with different lengths of wire installed. Strange, as the sensor with the shortest wire fits both banks and the sensor with the longer wire fits both as well. Why have they made it so hard?

Rockauto have the part  2349051 @ £83.50 which are the ones I bought - mine is a 2007 model and I have had no issue with them since install (I think nearly 3 years now?) You can see from the attached image they have of the sensor that its scribed with the product info s/no on the sensor body. Did the one you purchased as new have this?

[is200 Newbie]

I have just compared the packaging of the sensor - the picture I posted on page 1 to the picture you have posted and they are quite different - do you still have the box as I can compare it to the one I have as I kept the good sensor I had in it.

The Japanese on the box I would have expected to see translated to "Air/Fuel sensor" but it is nothing like it in comparison to the translation site on Google. OK, I accept the packaging will change over the years but the box must show the part number etc ...(afterall the seller did say it was new) ...was it not working and it was re-sealed and sold on or an actual fake itself? Did you get the small tube of thread grease with it should be supplied with one? Is the seller still active on eBay?

[johnatg]

The box print says O2 Sensor - search on Google for 'Translate to Japanese' - first result is a box - you put the english  (ie sensor) on the left and the japanese appears on the right - exactly the same as the box. You don't need to translate O2 - element symbols and numbers are the same in english and japanese!

That doesn't mean it's genuine of course!

I'm wondering - could these be downstream sensors, rather than upstream? Presumeably the screw fitting is the same - are the electrical plugs the same?

[normski2]

Don't think so as the downstream sensors have a fitted shield around the body.

[james250]

It's definitely not downstream sensors. they are AFR sensors for sure but I now believe they are fakes. Because on the side of the box it had a photocopied colour toyota barcode. I am still waiting for my Techstream to be delivered to run live data on the sensors to see what kind of readings they are giving. If they are off I think I will go for the DOX-0263 as I believe those are the correct Denso equivalent in Europe. 

[PT99999]

Hi all, I did B1S1 and B1S2 sensors today.  Confirm denso sensors as described earlier in this thread seem good, I could only get an equivalent blueprint b1s2 sensor, without the shroud; but hacked old shroud off and seated other side of the compression seal, works ok.  Had a real issue with seized b1s2 sensor, but used ferrosol and blowtorch, plus using car weight to help turn the breaker bar and release it.  Don't need to remove seats, can remove some trim and lift carpet in front (driver in UK) to access plug and the floor grommet hole etc. One note is that offset 22mm O2 sensor socket (with slot) and having medium depth is needed (not straight inline or short depth socket), the one with star aperture for breaker bar means the job is possible, it's not if one doesn't have this tool.  Note that b1s1 sensor is much easier, but quite tight access, the dox-0263 works nicely.

Anyway, takes around 4hrs for both, incl overcoming seized sensor, few cups of tea and some cigs.

Now just to get micro fuses to replace the 7.5amp obd fuse that I blew resetting the codes. Who knows how.

Cheers

[Staci Douglass]

Hi, I have a 1999 lexus es300. I'm a little confused on where these 02 sensors are located. Everyone is saying under the fuse box but when I lift my hood it looks to be almost in the center and visible without removing anything and it seems to be connect to exhaust