02 sensor advice

[Gunnster]

On 3/7/2024 at 5:40 PM, Nordboy70 said:

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.

I managed to swap the sensor yesterday, I was very, very close to giving up but managed to get the old sensor off. As you said the lights don't go away immediately, so I need to take it out to see if it makes any difference. Fingers crossed. Thanks for the advice, much appreciated.

[Thejaffe]

Hi. 

I've replaced the post cat o2 sensor on an Aygo with oem Bosch. The 3 lights came up on dash and scanner also pointed to this sensor.

It still takes a good 5 or more minutes for the readings of this sensor to kick in whereas the first sensor reads immediately. 

The sensor is a heated one which I thought would read much quicker.  

Is this normal or should it read much quicker.

I tried my Ssangyong and a Corsa and the post cat sensors on these read immediately.  Another younger Corsa behaved the same as the Aygo.

There is 12V being supplied to the heater of the sensor. It reads a steady 1.275V until it kicks in.

Any thoughts?

 

[Nordboy70]

On 4/7/2024 at 11:31 PM, Thejaffe said:

Hi. 

I've replaced the post cat o2 sensor on an Aygo with oem Bosch. The 3 lights came up on dash and scanner also pointed to this sensor.

It still takes a good 5 or more minutes for the readings of this sensor to kick in whereas the first sensor reads immediately. 

The sensor is a heated one which I thought would read much quicker.  

Is this normal or should it read much quicker.

I tried my Ssangyong and a Corsa and the post cat sensors on these read immediately.  Another younger Corsa behaved the same as the Aygo.

There is 12V being supplied to the heater of the sensor. It reads a steady 1.275V until it kicks in.

Any thoughts?

 

Probably me, as I'm very far from any sort of expert, but I'm not sure what you're actually asking? Are you saying that after changing the o2 sensor, the warning lights are still on permanently? Or they then they go off after a while? That the o2 sensor isn't working? A heated sensor isn't really required unless you do loads of short journeys, but should take readings quicker than non heated. I actually have no idea if the one I replaced is heated or not.

When I replaced mine, I had to run the car for a while, then turn off, and on again before the warning lights cleared, touch wood, they haven't come back on yet (well, my daughters car, so if she follows my wife, wouldn't notice warning lights anyway!!!)

[Thejaffe]

The warning lights and code were for the old sensor that I replaced. No warnings or codes now. 

Just was curious as to why the Aygo rear o2 sensor took some time to start reading whereas the ssangyong and vauxhall ones read straight away.

[Offbeat Dave]

Thanks to the posters on this thread. Just replaced the post-cat O2 sensor on daughter's 2018 Aygo x-play with the one pictured as supplied by my trusted local parts people. Bit of a pig to undo the old one, but heating exhaust around it (protecting underside of car) and slacking off the sensor with water allowed us to get it off with a proper O2 socket, bar and pipe whilst up on axle stands.  New sensor fitted, code cleared and haven't come back. Interestingly, the O2 fault code also disabled the speed limiter functionality. Every time I cleared the code with the faulty sensor it restored functionality until the code returned. 

Anyway, many thanks everyone.