Depends on the code readers ability to stream the data. You need to be able to interpret it as well. If the sensor does have a hard failure ,like a blown heater circuit or its stuck in one end of the range it will throw a code. If it is slow but in range or not accurate but in range no code will be...

Do you have a picture of where the O2 sensors might be located?

Thanks for the quick reply. Will the code reader tell me which one is malfunctioning?

Also where is the sensor found?

Thanks !

Hello,

New to Volvos and recently bought an 05 S40 2.4i.

Looking for instruction on how to change the O2 sensors on my car.

Any help much appreciated.

I have some other repairs that needsto be done

!. Front bearing
2. Muffler and pipe
3. SRS module
4. Possibly steering column