|
Can anyone tell me what a O2 Sensor does, I believe it's something to do with the exhaust.
|
|
Detects oxygen in the exhaust gas - a sign that fuel isn't all being burnt.
|
|
Thanks for quick reply, is it a serious problem?
|
|
If it's bringing the ECU light on, chances are it's the sensor at fault rather than your engine chucking a load of unburnt fuel down the exhaust (might have other symptoms if that were the case!). Cure is usually fitting a new sensor (looking at other threads the advice is to stick with genuine parts rather than getting a universal sensor). Time to phone your Hyundai dealer - their parts aren't cheap so make sure you're sitting down before you pick up the phone! ;-)
|
|
Forgot to say cars made after 2001 have more than 1 O2 sensor, so you might want to get them both tested to see which one's at fault. Take it to an independent for this, but buy a genuine Hyundai part if it needs a new sensor.
|
Too add to Greg's response, it's quite possible for there to be other engine faults which can cause lambda or oxygen sensor codes to be stored. Any fault which seriously affects how the engine is fuelled can set this code - for example a vacuum pipe off, or inlet manifold gasket leak, meaning that unmetered air is drawn into the engine will cause the long term fuel trim (or perhaps called the integrator or block learn) to go out of limits.
i.e., it's usually best to check for other engine faults *before* fitting a new sensor. Effectively, obtaining the fault code is the first step in diagnosis, giving you a pointer in this case that there's a potential fuelling fault. Further diagnostic steps will tell you if it's an O2 sensor fault or a more general fuelling fault.
Number_Cruncher
|
Thank You once again gentlemen.
The vehicle is still under warranty. I have tried to telephone my local dealer five times today but to no avail.
If you have a Hyundai, try not to breakdown in deleted - (although you didn't name the dealer, naming their location can still identify who you're referring to, and thus naming / shaming, which we don't allow - DD} as they are as much use as a return ticket on the Titanic.
Better to breakown in Shrewsbury where they are "top notch"
|
h/man
Could you give a bit more in the way of the context? You mention the oxy sensor and then a breakdown?
What tells you that you've got a sensor problem? What evidence of the problem [breakdown] is otherwise apparent - and how does an oxy sensor fault relate to it?
Start at the beginning and fill us in.
|
The full story.
On the way to Wales for our Holiday early last month, the vehicle started kangarooing just past Telford, the engine 'Malfunction Indicator Light' was on, managed to crawl into a Shrewsbury dealership and they connected the vehicle to the computer, where upon a fault was dianosed with the O2 Sensor.
They reset the sensor using the computer and offered to replace the sensor within two days as they did not have one in stock, but as we were billeted some seventy miles away I declined the offer.
Yesterday the said light came back on.
|
|
No more kangarooing yesterday though? Possibly something else made the light come on - take to an independent for a full diagnostic. They'll be able to read the codes and find what made the light come back on yesterday. Ignore my post about buying a new O2 sensor - would be a complete waste of money if that's not the current fault.
|
|
|
h/man
I'd love to know how to "re-set" a failed oxygen sensor? Re-setting [clearing] the code is simple enough - if a bit pointless as it will quickly return.
Just because there's an oxygen sensor code doesn't necessarily mean that there's anything wrong with the sensor - there are many Lambda codes and most are for an incorrect SIGNAL from the sensor.
A quick listen in the engine bay for hissing from any disconnected vacuum hoses etc. would be one thing you could try.
There may well be two oxygen sensors in the exhaust; one pre and one post cat. Although they can fail, physical symptoms on that scale are very rare and the fact that the dealer doesn't stock them tells it's own story.
This could be more of a mixture fault setting oxy sensor codes than a sensor gone down.
|
|
|
|
