A2 EGR valve cleaning (engine management light)

[wiffers]

My wife's Audi A2 (X-reg 1.4 petrol) has an engine management light

"P0401 EGR system insufficient flow"
"P1190 Linear O2 sensor reference voltage, implausible"

They occasionally go off for a whuile, then return, so suggest the fault is borderline.

I believe the O2 message could be caused by the EGR one. From what I can gather the fault is likely to be a build up of carbon in the EGR valve, the return pipe, or around the EGR sensor. I'm hoping a good clean up will help.

So....

1. Where is this on a 1.4 petrol? Any guides on how to remove and clean the system? Estimates on how long it'll take?
2. Can I get the sensor out easier, if so where/how? It'd make sense to clean this first if possible as easy.

Ideas?

Thanks

[Crasher]

If you take off the throttle body you may find the pipe under it for the EGR is blocked on the end. There is no point cleaning the EGR valve itself. There is no EGR sensor as such, it uses the MAP sensor to detect the EGR flow. You may also find the throttle body is heavily clogged up, after cleaning it will need to be reset on a diagnostic machine as will the EGR valve if you replace it. If you don't set up the TB the idle may be extremely erratic and not setting up the EGR valve makes them burn out and the suppliers know this and will refuse warranty.

[wiffers]

Jeez - getting me worried.

So, take apart throttle body
clean
put back (do I need to set this up then?)
Reset EGR code

???
Hard job?

Thanks

[Crasher]

If you clean the TB you MAY need to reset it. When doing the reset it sometimes becomes necessary to delete the ECU leant valves. When you do this, if the EGR valve is stuck open, the engine can go nuts and the throttle not operate until a new EGR valve is fitted and matched, they throw up a MAP sensor code but this is a red herring. If you have full VCDS it is not hard, just sometimes frustrating getting them to behave after cleaning the TB.

[wiffers]

I don't have VCDS, and unsure my mechanic does (he has a multipurpose one), although I was thinking of getting for my Audi A4 at some stage.

I may put up with a warning light for the time being :p At least the cars works.

Is it easier to disable the EGR?

Thanks for your help

[Crasher]

No and it's illegal anyway.

[wiffers]

Oh OK I didn't know.

So it's not a purely mechanical job, but likely to cause more issues with regards to warnings and mixtures and sensors and things... this makes me kind of worried. I may just leave it and put up with the light, and get VCDS to peridocially check for other errors.

I guess there's no way of telling the system "please ignore this warning"?

Many thanks mate

[Crasher]

It is part of its emissions standards protocol, probably Eu4.

[wiffers]

It is part of its emissions standards protocol, probably Eu4.

Sorry I'm unsure what you're meaning here.

If you are referring to the MOT, it seems to get through fine.

If you're referring to the VAG codes, does that mean it's not possible to hide it or it is?

Thanks

[Crasher]

The car was built to a European protocol on emissions, at that time it would have been EU3 or EU4, now we are at EU6 and above. Sometimes the ECU can recoded to an earlier standard which takes away certain features, you should stick to how your car was made. If it is EU4, it is safe against the upcoming punitive emissions geofencing coming into the UK from around 2019 which will block non EU4> pertol and non EU6> diesel vehicles from certain areas.

[wiffers]

I don't want to actually change the way it works, just disable it flagging up as an error on the dash.

I assume not possible then... :(

[Crasher]

Not legally or responsibly.

[wiffers]

OKay thanks