my wifes audi keeps failing the emissions test.to much oxygen on the read out any ideas anyone help....cheers lee

[tamiya]

[ChuckFickens]

Oxygen??

That's not part of the test!

[Nkakamasembe]

The fact that MIL light has not come on may indicate,you have delayed replacing your air cleaner and or spark plugs.In the serious case its may be has a result of excess fuel pressure,leaky injectors etc.
Mind you it can also be a result of short trip driving habits,leaky exhaust pipe ,some systems are so sensitive that a minor exhaust leak would the emissions off. OR you could be missing the obvious what fuel rating is on your fuel lid?
Ensure no exhaust leak, correct fuel, work the cat real hot if you can get some good injector cleaner this might help.
By the is high reading at high idle or normal idle.
Is the car being tested against its correct year spec. Mind you current spec are strictor than a fews years back.This can happen if you have a cherished reg plate !!!!

[tamiya]

any ideas were the engine management chip is and the cats replaced no blows or leaks,and the 02 reading goes down at high revs then the co2 reading goes up and vice a versa at low revs....................help

[ramscooby666]

if its high o2 reading thats the air flow meter letting to much air in via the ecu (brain) it would find the fauilt and put the ecu fault light on so i would be checking all hoses under bonnet for cracks splits sucking air in first before i went down the road of putting the car on a dignostic machine or tech 2