Engine warning light but no error codes?

[tag1_uk]

Dear All,

 

My car is a 2002 Fabia Mk1 1.4 16V AUB engine code, 66,500 miles.

 

Recently the engine warning light came on, the first time this has happened.  I read the error and it was EGR flow excessive.  I reset the error but the light came back on about 40 miles later,  The error code then was EGR flow insufficient.  I took it to the local garage (not VW/Skoda) who said that the EGR valve had failed when tested on the bench so they replaced it and reset the error.  However the same engine warning light came back on about 30 miles later but my error code reader said that there were no error codes stored.  I went through the reset error codes procedure and the light went out but it again returned about 20 miles later.  I took it back to the original garage and they did a thorough investigation and could not find any error codes stored despite the light being on (and they confirmed that the new EGR valve is working correctly, giving the expected readings whilst the engine is running).  They advised that I'd just have to drive it around with the light on and take it to a Skoda dealer for a more thorough investigation.  Throughout the car has been working ok, maybe a bit hesitant and the tickover is not completely steady but then it is 14 years old and these things were never that great even when I bought it at 5 years old.  The other possible symptom I've noticed is that the smell you get from the cat when the engine is cold seems to be  noticeably stronger over the past few weeks than normal, just in case that means anything and I'm wondering if my fuel economy is a bit reduced too.  I'm not sure what to do next, I'm nervous of driving it in its current state but I am also wondering if it isn't worth throwing any more money at it at the main dealer since it's trade in value is only about £100.  I don't understand how the error light can be on but with no error codes stored?

 

Thanks for any advice.

Edited 7 April, 2016 by tag1_uk

[Breezy_Pete]

It's worth adding an approximate location to your profile, as there may be someone nearby willing to offer help.  For instance, there's a software package called VCDS that can be used to interrogate your car's electronic systems, via the OBDII port. I would scan your car with this for nothing if you were sufficiently close to me that you could get the car to me. Other members elsewhere in the country may be similarly willing.  You could also inexpensively acquire a suitable lead for this, and download the freeware version of the software yourself.

 

If there's a fault light on, the only reason to not be able to read the fault code is that the wrong equipment is being used to attempt it, as far as I know.

 

The EGR valve itself rarely causes any problems (but never say never, these cars are getting on a bit now and it has a moving part in a hostile operating environment). Usually the pipe that links the EGR gases into the throttle-body/inlet manifold is where any blockage occurs - at the throttle-body end - and no amount of money spent on new EGR valves will make any difference.

Edited 7 April, 2016 by Wino

[tag1_uk]

Thanks, I'm in Fareham in Hampshire.  The code reader I've got is an Xtool VAG401 for VW group vehicles, live data/EOBD/OBD2/OBDII. (http://www.amazon.co.uk/Xtool-Diagnostic-Vag401-Skoda-Vehicles/dp/B016IDXE78?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o08_s00)

 

I hope that this equipment would cover most eventualities?

 

I'm not sure what equipment the garage used.

 

The garage didn't comment on the condition of the EGR tubing, I think they simply decided that the valve was faulty when tested so they replaced it, I'd presume they'd clear out the tubing as part of the job.  I didn't know whether it was worth separately getting the throttle body cleaned including the EGR entry and the re-adapted but without knowing what the error is, I was reluctant to speculatively start doing jobs on the car.  I have had the throttle body cleaned regularly throughout the car's life and I normally use Shell super unleaded petrol and the occasional Redex fuel additive so I'd hope that the throttle side of things would be in reasonable shape.

[Breezy_Pete]

Have a look at this thread. On the original version of these it's a faff to clean the entry point/ internal connecting tube of the EGR at the TB end, so no, I very much doubt that your presumption about what the garage would do is correct, unfortunately.

Fancy fuel/additives won't make any difference at this point either, the fuel is injected well downstream of the TB, they may benefit running due to octane rating though, on this engine.

[rum4mo]

While the trade in value, or the absolute max that webuyanycar have given that car is £100, it could be worth a lot more to you, so yes I agree get that TB area cleaned out, I think these car also "like" a new ERG valve "aligned" to the controller - in the same way as the TB is done - do you think that that non VAG garage did that either?

[tag1_uk]

I checked the EGR valve adaptation with my code reader and it checked out ok.  I'd have thought a dirty connection between the EGR pipe and the throttle would have brought up another EGR error if this was the cause of the engine light coming on?  I still don't understand how the light can come on but not trigger the storage of an error code.  Thanks for the link to the throttle body clean/EGR clean, I might consider having a go, I think my code reader can do the adaptation which is otherwise the main stumbling block to messing with these things.

Edited 7 April, 2016 by tag1_uk