Emission Light on Dash Board

[jamo79]

Hi All,

Drive an A4 04 1.8 Turbo and my orange emission light has come on. Have browsed a few other threads and I take it I should have a VAG Com test to diagnose the fault? When I was having a look at the engine I noticed that this part at the top of the engine at stages was sucking in air on just 1 side is this right and if so what does this do? as I am not sure if it has always done this. Any help would be great thanks.

 

[blackpool1974]

I have just come online to post exactly the same thing.

If you use VAGCOM it will report fuel trim lean bank 1 (add)

Basically the engine thinks it isn't getting enough fuel so keeps the injectors open a bit longer (apparently) had this so called problem for a couple of months, since Audi serviced my 1.8t Cab

Symptoms are when the engine is at idle, it is very jerky, you can travel for hundreds of miles with no problem, then you stop and the light will come on !! then if you get rid of it, it takes about ages to come back, depending on how much you stay idle

I also noticed the sucking off air, if you put your finger to the left of the disc, the engine cuts out, I think it is a vacuum pipe ?? not very clued up unfortunately

So experts come along and put us out of our misery




You can check your current state of trim by using VAG-COM on engine measuring block 032

The first two fields will have percentages. The first field tells the fuel trim at idle (Additive).


The second field tells the fuel trim at elevated engine speeds (Multiplicative).


Negative values indicate that the engine is running too rich and oxygen sensor control is therefore making it more lean by reducing the amount of time that the injectors are open.


Positive values indicate that the engine is running too lean and oxygen sensor control is therefore making it richer by increasing the amount of time that the injectors are open.



mine is at 13% on the first field
mine is at 4% on the second field


Apparently it kicks the light on at 10%

 

[blackpool1974]

Just had this email from an expert

the breather check valve you can see leaking needs to be replaced which on your car is 06A 129 101 A but this has been superseded to 06A 129 101 D and costs £22 from Audi.

 

[jamo79]

Hi All,

Many thanks for your updates.

Thanks
James