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VW Golf MkIV - Exhaust Emission Warning  
VW Golf MkIV - Exhaust Emission Warning - newby06
I have recently bought a MkIV VW Golf S (51 reg)thats done 50k miles.

About 5 minutes after leaving home today the Exhaust Emission warning light started blinking, then after a couple minutes of blinking it stayed lit up and it hasnt gone away.

Does anyone have any idea of why this would happen? The manual says that it could be something to do with a Lambda probe fault?
Is there any way I can confirm what exactly is wrong with it?

The car generally seemed to be running fine but I am a bit worried that this is going to get expensive.

Tags: technical issues used cars exhausts

VW Golf MkIV - Exhaust Emission Warning - Andrew Moorey (Tune-Up)
You are going to need to find someone with a scan tool to identify the code(s) that will be logged, then carry out the neccessary tests to pinpoint the problem.
Certainly the O2 sensor could be a problem area but it may not be as simple as replacing the sensor as it could be a faulty sensor earth, heater supply, heater earth or signal wire fault, so don't rely solely on fault codes for your diagnosis but, having said that, on a more cheerful note VAG are exceptionally accurate with their codes.
Andrew
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VW Golf MkIV - Exhaust Emission Warning - newby06
Cheers for that Andrew.
By coincidence i have the car booked in to have some other work done on it next tuesday so I will ask them to look at this as well. Do you think I would do any damage to the car it if i was to keep driving it until then?
VW Golf MkIV - Exhaust Emission Warning - nambarry
My beetle had the light come on, when i put it in to get serviced all they told me it had a lambda fault as there is two lambda's on this car i asked which one was faulty they said they would have to take the car back for 3 hours to pin point the fault, so i told them where to go rip off merchants

The car has sinced passed its MOT emissions no problem with it running very slightly rich very minutely

I'm going to buy a scan tool OBD2 from e-bay for £30 and fault find it myself , you can also turn the fault lights off with this tool when it has been repaired
VW Golf MkIV - Exhaust Emission Warning - newby06
Yeah I get the feeling that they will try to tell me that it will take some time to pinpoint the fault - at around £100/hr it could be quite expensive.

And they probably wont be able to fit me in for the next couple of weeks in which time something else will probably go wrong with this.

It got a MOT in november so it is not due for another test for another year. I might check out that scanner that you mention.

VW Golf MkIV - Exhaust Emission Warning - newby06
Yeah I get the feeling that they will try to tell me that it will take some time to pinpoint the fault - at around £100/hr it could be quite expensive.

And they probably wont be able to fit me in for the next couple of weeks in which time something else will probably go wrong with this car.

It got a MOT in november so it is not due for another test for another year. I might check out that scanner that you mention.

VW Golf MkIV - Exhaust Emission Warning - nambarry
I have also been told flashing light means an active fault when the light goes steady the fault has cleared.

My light also came on about the 50k ish mark

Also been told these lights are easily triggered and nothing to worry about by a VAG mechanic told me its an easy way to extract £500 form some mugs so the service managers can hit their targets, these lights could easily be switched off but VAG would rather make a song and dance and an easy £500
VW Golf MkIV - Exhaust Emission Warning - Andrew Moorey (Tune-Up)
The light blinking erratically is the system picking up the fault, when it goes steady the system has dropped into LOS mode (Loss Of Signal) or 'limp home' whereby the ECU is running the engine on a preset programme and by and large ignoring the sensors. Modern systems are so good the difference in performance can be barely perceptible so you shouldnt do any damage short term.
Be careful going down the cheap scantool route. Whatever you do, DONT scan the airbag controller.
Andrew
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VW Golf MkIV - Exhaust Emission Warning - jc
LOS(limp 'ome) actually stands for LIMITED OPERATION STRATEGY tho' loss of signal is pretty accurate.
VW Golf MkIV - Exhaust Emission Warning - Andrew Moorey (Tune-Up)
Just testing!!!!

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VW Golf MkIV - Exhaust Emission Warning - Michael Mc
Hi - My emission light issues were solved in my Golf (mk4 GTi 1.8T) with a cleaning of the MAF sensor (or replacement depending on circumstances) and also the cleaning of the throttle bodies.

The efficiency of the two lead to triggering the emissions light. Not an expensive fix either!

HTH

Michael

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