Emissions Light on Audi A3 55 Reg

[AudiA355]

Hi,
My 1st post........ Bought an Audi A3 55 Reg (only 25k miles) from a family friend. The emissions light was on and very strangely the exhaust crossbox needed changed due to fallen baffles (was told this was not a costly fault) ehmm. Got the exhaust fixed then I took it to a well known garage as the mechanic owed me a favour. I dont know what the exact fault (message) was though he said it was the front lambda Sensor that needed changed. Due to My engine code BSE I had to get the sensor from Audi, mechanic fitted it and guess what the light came back on. . . Mechanic then said it could be the rear lambda sensor that needs changed or the CAT (expensive). Cant afford all this trial and error :1zhelp:

[stusA3]

hi i have got a 2.0ltr fsi sport a3 on a 53 plate and my emission control light came on. luckily for me it was still in warranty from the garage i bought it from but they had to change the emission control unit which is located at the back top part of the engine. maybe this could be ur problem. have you had it on a diagnostic machine???????

[AudiA355]

Just took it to an Audi specialist garage and its booked in for Tuesday..... The mechanic connected a device which he said is like a flight simulator and reads all happenings while the car is sitting idle (which he said he will look at the readings from it later) - he then connected the diagnostics machine and showed me what the 2 lambda sensors were monitoring - turns out . . . . the diagnostics is picking up a fault with the CAT. He did say that as it has only done 28k miles he hopes it just needs a clean out so he will put a liquid through the car to clean any build up of dirt caused by alot of small journeys - he also mentioned that it will help the small rumbling when on idle.

Hope this works

[AudiA355]

:zx11: What a waste of another £100. My Emissions light is back on.
The garage put a liquid through to clean out the throttle valves and CAT. Light is on and garage told me that I need a new CAT and quoted £560. Not hurrying to get this fixed. Or Should I?????
Plus the car is still shuddering when idling. Not a happy bunny. Any ideas re- shuddering?

[dee_clare]

Hi, I'm in the same situation - I have a 53 reg 2.0 FSI sport which has done 51k miles. Nothing seemed wrong with it at all before I took it to Audi for it's service where they found a load of messages on the fault sensors; as none of the lights had come on yet I left it, and lo and behold a few weeks later the emissions light came on. Took it into a local Audi specialist (dealer quoted £1500 for work) and it apparently needed a new NOX box (the bit that controls the balance of emissions from the exhaust) - all fine, paid siilly amount but got it replaced. Three weeks later the light has come on again and is reporting two different fault codes - one for the recirculation of noxious emissions and random ones which seem to chance with little consistency. Am starting to think that the sensors on the car are way too sensitive as there does not seem to be a loss of performace which would be in line with the latest fault code. It's driving me mad as it feels that the lights just come on wily-nilly. Totally agree with the previous poster - can't afford to keep changing bits when where might be a) nothing wrong with it, or b) something major which we will only find once all these other costly bits have been replaced. Help please!

[AudiA355]

I think your right dee_clare, when the mechanic showed me what the 2 lambda sensors were recording, it only showed a slight movement on the back lambda sensor rather than no movement as the cat should get rid of anything ( nothing much to worry about (i hope) also it is passing its emissions so bugger it the light can stay on, the only thing I'm worrying about is when I sell it or trade it in.

[FSI Sport]

My 53 plate 2.0 FSI Sport also developed this fault, a friend ran a check and came back as the EGR (exhaust gas recirculation) valve, so I had it in bits and it was a bit furred up and seemed to have got stuck, however the driver wheel for this valve has eaten some of the teeth off the plastic cogged wheel that opens the valve, i'm loathed to pay out for a complete new valve when all i need is a plastic cog.

Any one got a spare?

Gareth.

[dee_clare]

Hi Gareth,
That's exactly what has gone wrong with mine. I took it to the local Audi specialist (Audi dealer was way too expensive) today to finally get it fixed (the same light was still on, but oddly with no loss of performance), and it was the EGR valve and the same issue as you. I asked the same question as you and unfortunately it's not as easy as getting a new cog, it affects the sensor and doesn't fix the problem. I had mine done for £240 - where are you based - maybe you could go to my chap too? He looks after a couple of my friend's cars (and has replaced my radiator and cambelt - don't you just love the new model?!)who all have new Audi's so he knows what he's up to.
Let me kniow if you want his number.
Good luck,
Dee

[FSI Sport]

Thanks, I managed to reposition the larger plastic cog just off the damaged part and this seems to have cleared the fault. Car runs fine now we got an average MPG of 43mpg over 200 miles yesterday so no issues anymore.

Gareth.:beerchug:

[dee_clare]

Nice one, 43 MPG - result!

Dee

[iankeay]

hi peeps dunno if i should be really saying this but i've had problems with my emisions light on my 53 plate A3. Thought that if its only the exhaust emissions then the worst thing that could happen was the exhaust would drop off. Anyway drove the car for at least a couple of months with no problems. Eventually had it serviced and lights now gone off and (touch wood) no problems yet.