02 sensor advice

[mitford]

Hi all, my daughters 2018 aygo came up with the engine warning light, traction control and tyre pressure warning lights, after reading it seems it's quite common and that its more than likely an o2 sensor. I have put a diagnostic on it and it has come up with the p0139 o2 sensor slow response bank 1 sensor 2 (post cat). ive read that even buying a good sensor like bosh can still throw up an error. My question is does anybody know what the OEM sensor is as toyota want £165 to supply it if i can find it cheaper all the better

.

[flash22]

Bosch is the oem - Bosch 0 258 030 446 Lambda Sensor - Toyota part No. 89465-0H050 or 89465-0H070

A decent seller or 2

https://www.ebay.co.uk/itm/334702992421?

https://www.ebay.co.uk/itm/195262512979

[mitford]

20 minutes ago, flash22 said:

Bosch is the oem - BOSCH 0 258 030 446 Lambda Sensor - Toyota part No. 89465-0H050 or 89465-0H070

A decent seller or 2

https://www.ebay.co.uk/itm/334702992421?

https://www.ebay.co.uk/itm/195262512979

ah i see thank you, i was getting confused as in this post it says dense is the OEM 

 

[flash22]

Mk1 Aygo's use Denso the Mk2 uses Bosch, 2014 is the change over year Mk1 > Mk2 (05/2014 - 2021)

[mitford]

58 minutes ago, flash22 said:

Mk1 Aygo's use Denso the Mk2 uses Bosch, 2014 is the change over year Mk1 > Mk2 (05/2014 - 2021)

i see, thanks for your help👍

[mitford]

On 7/29/2023 at 10:46 AM, flash22 said:

Bosch is the oem - BOSCH 0 258 030 446 Lambda Sensor - Toyota part No. 89465-0H050 or 89465-0H070

A decent seller or 2

https://www.ebay.co.uk/itm/334702992421?

https://www.ebay.co.uk/itm/195262512979

I finally managed to get the thing off, it was stuck. Anyway the number it has in it is 0258 030 310 I wonder if it’s been changed before 🤔

[flash22]

41 minutes ago, mitford said:

I finally managed to get the thing off, it was stuck. Anyway the number it has in it is 0258 030 310 I wonder if it’s been changed before 🤔

Second line of numbers as i listed above 89465-0H050 that looks to be the original part

Both 0 258 030 310 and 0 258 030 446 cross-reference to Toyota 89465-0H050

 

0 258 030 310 looks to be the older Bosch part number replaced by 0 258 030 446

[mitford]

1 hour ago, flash22 said:

Second line of numbers as i listed above 89465-0H050 that looks to be the original part

Both 0 258 030 310 and 0 258 030 446 cross-reference to Toyota 89465-0H050

 

0 258 030 310 looks to be the older bosch part number replaced by 0 258 030 446

Nice one thanks again 👍🏻

[mitford]

On 8/23/2023 at 1:44 PM, flash22 said:

Second line of numbers as i listed above 89465-0H050 that looks to be the original part

Both 0 258 030 310 and 0 258 030 446 cross-reference to Toyota 89465-0H050

 

0 258 030 310 looks to be the older bosch part number replaced by 0 258 030 446

Replaced it a few days ago with one from the links you provided all good now. Cheers 👍🏻

[Nordboy70]

Can I ask how anyone managed to get this changed? My daughters 2014 2nd gen Aygo has thrown up this fault and my obd says o2 sensor. I want to get the car up for sale (don't want to but she's now doing her test in an auto) so need to change it asap.

So, got the part from Germany at a 3rd of the price toyota wanted. BUT, for the life of me can't work out how I'm going to get the old sensor out. It's stuck solid and I can't get enough space around it for leverage!! 

My idea of saving a few ££ may end up costing me.

[flash22]

you will need an o2 sensor socket or deep socket and lop the wires off it

run the car get the exhaust warm it may crack loose

 

ps, I would avoid the Aygo automatics and look at a Yaris 2012-17 if you like your sanity

[Nordboy70]

Thanks, I did think of that, unfortunately I don't have a 22mm deep socket so will have to buy one. 

[mitford]

1 hour ago, Nordboy70 said:

Can I ask how anyone managed to get this changed? My daughters 2014 2nd gen Aygo has thrown up this fault and my obd says o2 sensor. I want to get the car up for sale (don't want to but she's now doing her test in an auto) so need to change it asap.

So, got the part from Germany at a 3rd of the price toyota wanted. BUT, for the life of me can't work out how I'm going to get the old sensor out. It's stuck solid and I can't get enough space around it for leverage!! 

My idea of saving a few ££ may end up costing me.

Post or pre CAT? My daughters was post cat I’m and I had the same trouble. Ended up buying a tool from eBay that someone makes which clamps round the sensor nut and you tap it wi the a hammer m, done the trick for me 

https://www.ebay.co.uk/itm/385208493434?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=kzcOPj_pTfW&sssrc=4429486&ssuid=Mr7ktYPiRBS&var=&widget_ver=artemis&media=COPY

[Nordboy70]

8 minutes ago, mitford said:

Post or pre CAT? My daughters was post cat I’m and I had the same trouble. Ended up buying a tool from eBay that someone makes which clamps round the sensor nut and you tap it wi the a hammer m, done the trick for me 

https://www.ebay.co.uk/itm/385208493434?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=kzcOPj_pTfW&sssrc=4429486&ssuid=Mr7ktYPiRBS&var=&widget_ver=artemis&media=COPY

My obd wasn't 100% clear, so I'm going pre cat at the moment with fingers crossed. It was a 139 code, I thought that was pre cat?

[mitford]

5 minutes ago, Nordboy70 said:

My obd wasn't 100% clear, so I'm going pre cat at the moment with fingers crossed. It was a 139 code, I thought that was pre cat?

Mine code was 139 bank 1 sensor 2 (post CAT)

[Nordboy70]

1 hour ago, mitford said:

Mine code was 139 bank 1 sensor 2 (post CAT)

Damn, that'll learn me. Just re-run the obd and that's what mine says. Totally different sensor? Or is it the same? Going to have to find that one now I suppose!!

[Nordboy70]

2 hours ago, flash22 said:

you will need an o2 sensor socket or deep socket and lop the wires off it

run the car get the exhaust warm it may crack loose

 

ps, I would avoid the Aygo automatics and look at a Yaris 2012-17 if you like your sanity

Thanks, we nearly bought an Aygo auto but it got sold before we could see it. Maybe we'll look elsewhere for an auto for her then.

[mitford]

18 minutes ago, Nordboy70 said:

Damn, that'll learn me. Just re-run the obd and that's what mine says. Totally different sensor? Or is it the same? Going to have to find that one now I suppose!!

Same one as I had, so put your head under the front of the car and you can see it. I ad two wheels on the kerb and two in the road to replace it with the tool I posted earlier as it was stuck and the deep reach socket wouldn’t move it. 
 

if you read further up I bought that sensor form the link on eBay and it’s been fine ever since 

[Nordboy70]

11 minutes ago, mitford said:

Same one as I had, so put your head under the front of the car and you can see it. I ad two wheels on the kerb and two in the road to replace it with the tool I posted earlier as it was stuck and the deep reach socket wouldn’t move it. 
 

if you read further up I bought that sensor form the link on eBay and it’s been fine ever since 

 

Thanks, I've ordered both the sensor and the tool from your links.

[Vandals01]

Getting the O2 sensor off is always a challenge.  The most effective method (at least for me) is:

1. Spray the socket with generous amount of penetration fluid
2. Chop the electrical wires off, 
3. Put a 22mm ring spanner on it.
4. Hit the ring spanner with a mallet.

There are Oxygen sensor sockets out there.  However, cheap ones have a tendency to spread then slip under immense torque, potentially rounding off the hex on the sensor.

I supposed it can also be done using a deep socket with a ratchet, but you run the risk of damaging the ratchet in the process.

[Nordboy70]

8 hours ago, Vandals01 said:

Getting the O2 sensor off is always a challenge.  The most effective method (at least for me) is:

1. Spray the socket with generous amount of penetration fluid
2. Chop the electrical wires off, 
3. Put a 22mm ring spanner on it.
4. Hit the ring spanner with a mallet.

There are Oxygen sensor sockets out there.  However, cheap ones have a tendency to spread then slip under immense torque, potentially rounding off the hex on the sensor.

I supposed it can also be done using a deep socket with a ratchet, but you run the risk of damaging the ratchet in the process.

Yeah, I'm not looking forward to doing the job tbh. I'll keep the above in mind. I have got various sensor sockets and bought the tool that Mitford linked too. I'm expecting the worst so hopefully will go better.

[Nordboy70]

Well, after all that it was ok. I just used the standard O2 sensor tool and a bit of brute force. The warning lights stayed on though, so I thought I'd changed the wrong one or that both had gone. I ran the car for a while, turned it off and on, eventually they went off. Not sure if it was time or my obd reader sorted it.

Anyway, the trusty Aygo is now clean, on auto trader and up for sale.

But, against all advise, I've now bought the daughter, well, she wanted one, an Auto Aygo, so that's what we've got. Same age, slightly more miles, but she's driven it today and she's happy.

[flash22]

Just a word of warning, clutches are not cheap to do on the MMT 60-70k is about right for an MMT clutch, slow low speed driving can take its toll

these gearboxes work a lot better in manual mode

[Gunnster]

On 2/10/2024 at 6:19 PM, Nordboy70 said:

Well, after all that it was ok. I just used the standard O2 sensor tool and a bit of brute force. The warning lights stayed on though, so I thought I'd changed the wrong one or that both had gone. I ran the car for a while, turned it off and on, eventually they went off. Not sure if it was time or my obd reader sorted it.

Anyway, the trusty Aygo is now clean, on auto trader and up for sale.

But, against all advise, I've now bought the daughter, well, she wanted one, an Auto Aygo, so that's what we've got. Same age, slightly more miles, but she's driven it today and she's happy.

Hi all, first time poster but I've read this thread several times as it describes my issue.

 

I have a 2016 Aygo with the engine lights on for a few weeks then go off and then reappear for a week or two. The garage said the code was O2 sensor, but the emissions were fine as it passed MOT no issues. The sensor was not replaced, alarm was cleared but its now back after a couple of weeks. This sensor looks like something I could replace on the driveway but can you confirm the 2016 Aygo has a pre and post CAT sensor? Is the post CAT sensor the most prone to failure? The eBay links in the thread show the sensor to be reasonably priced, so I'm happy to have a punt and swap it myself. Could anyone post pictures to where these are located on the vehicle please? Also I've noticed fuel economy is in the low 40s so could that also be pointing to the sensor? Many thanks.

[Nordboy70]

I have limited spannering skills and changed the post cat sensor myself. I did buy a sensor removal kit from Amazon which made the whole thing easier. Still needed a fair bit of effort,but managed it. After replacement, ran it for a while, turned it off and on again and the lights disappeared. Didn't need to reset them, just be patient.

I haven't got any pics of when i did it. If you jack the car up and look at the exhaust downpipe it'll be really obvious where it is.