Exhaust emissions warning light

[laura_82]

When i 1st got my car within a few days the exhaust emissions light came on then next time i started car up it had gone. My bf thought it might have just been a bit of bad petrol or something. Now yesterday ( bout 3 weeks later) it came on again and was still there when i started up again. Im not sure what i should do as in the manual it says to take it to a dealer. Has any1 else had this problem?

[RITCHAT]

When i 1st got my car within a few days the exhaust emissions light came on then next time i started car up it had gone. My bf thought it might have just been a bit of bad petrol or something. Now yesterday ( bout 3 weeks later) it came on again and was still there when i started up again. Im not sure what i should do as in the manual it says to take it to a dealer. Has any1 else had this problem?

Could be a sensor that is either dirty or needs replaced does your car have a full service history with it and the type of oil used.

This should be looked at as a matter of urgency I am sure that it will be resolved quickly once put on the computer.

[RUM4MO]

When a fault occurs the warning light will come on, if no faults, including this one occur remain, the light will go off after maybe 6 or 7 engine starts. So, that means that your car did have a fault - but it "went away" and so 6 or 7 engine starts later the light went out. What has happened now is that a fault, or the original fault, has appeared/re-appeared, but might have gone again. Without a scan tool you will never know what it was. What engine does your car have? One thing, if the car runs for a shortish time before the fault appears then I'd think that it would be a lambda probe, as their signals are ignored until the engine has warmed up (as before then even the probe itself would not be up to operating temperatures). If the fault starts to appear as soon as the engine is started, it will be something else usually - remember of course if the car had already been previously running with the warning light on then you can not work anything out in that respect. If you or your BF feel the need to look into what is wrong, then maybe consider buying a scan tool from Gendan or another place - www.gendan.co.uk sell a VAG simple scan tool for £40 delivered,m I've got one and they work, BTW garages charge more than that just to carry out a diagnostic check on the car!

[Jollus]

Yeah I agree the scan tools are useful but sometimes they dont help to find the exact fault. E.g. in the case of my continued problem of the exhaust emission warning light coming on all the time. The scan tools will tell you the fault is Lambda probe bay 1 or 2 but I have replaced them with genuine dealer parts an the light still comes on once a month. lol.

In the case of the topic at hand I think that the fault that came up on the car may still be in memory and could be retrieved using a laptop? Im sure old DTC faults that arent cleared appropriately are still there the next time that a laptop scans it?

[laura_82]

How do i use my laptop on it though? Im thinking about buying my own fault code reader, my bf has 1 but hes never around when the light comes on! Can any1 suggest something thats not that pricey as im still paying off my holiday among other things! Well we serviced the car last weekend and i havent seen it come up since, but this seems like a common thing with the polo? I dont want to take it anywhere yet as ive only just got it and dont wanna be forking out more cash!

[laura_82]

When a fault occurs the warning light will come on, if no faults, including this one occur remain, the light will go off after maybe 6 or 7 engine starts. So, that means that your car did have a fault - but it "went away" and so 6 or 7 engine starts later the light went out. What has happened now is that a fault, or the original fault, has appeared/re-appeared, but might have gone again. Without a scan tool you will never know what it was. What engine does your car have? One thing, if the car runs for a shortish time before the fault appears then I'd think that it would be a lambda probe, as their signals are ignored until the engine has warmed up (as before then even the probe itself would not be up to operating temperatures). If the fault starts to appear as soon as the engine is started, it will be something else usually - remember of course if the car had already been previously running with the warning light on then you can not work anything out in that respect. If you or your BF feel the need to look into what is wrong, then maybe consider buying a scan tool from Gendan or another place - http://www.gendan.co.uk sell a VAG simple scan tool for £40 delivered,m I've got one and they work, BTW garages charge more than that just to carry out a diagnostic check on the car!

Oops sorry i forgot to answer you! The engine is a 1.2

[RUM4MO]

Ah, 1.2 - well I'd go ahead and buy that cheapish stand alone scan tool that I suggested as it should point you in the right direction - these 1.2 engines seem to cause more problems than the 1.4 ones!

Once you have got this tool and started writing down a list of the codes you are getting, and clearing them, maybe search elsewhere on this forum and the Seat one (Ibiza) and the Skoda one (Fabia) using the terms "1.2 engine problems" - then you should find out how to sort this.

[RUM4MO]

Yeah I agree the scan tools are useful but sometimes they dont help to find the exact fault. E.g. in the case of my continued problem of the exhaust emission warning light coming on all the time. The scan tools will tell you the fault is Lambda probe bay 1 or 2 but I have replaced them with genuine dealer parts an the light still comes on once a month. lol.

In the case of the topic at hand I think that the fault that came up on the car may still be in memory and could be retrieved using a laptop? Im sure old DTC faults that arent cleared appropriately are still there the next time that a laptop scans it?

Yup, any logged faults will still be held in memory unless the battery has been disconnected, that is the very reason why anyone using a scan tool should record all listed fault codes, then delete them and then see what gets logged the next time - and repeat as necessary while trying to sort the problem.

In the case of Lambda probes, various codes will relate directly to them having failed internally, but some will be the effect of another problem - like mixture for instance. More expensive tools will let you look at live data so that you can see what the probe is doing with changing conditions.

Like any tool, a scan tool is not a tool to end all other tools, so without any other car knowledge, like a socket set, it will not help you much, having said that, without it you could be very much in the dark, with it, you have a starting point to let you try to work out what is happening.