Help- failed NCT emissions test twice

[Alan1001]

Does anyone have any advice for me to get my car past the emissions test?

I have a sirocco 1.4 bluemotion tsi 2010. The car has failed the last two emissions test, results are listed in the below .

I’ve taken the car to mechanic and they said the car isn’t displaying any error codes. Has anyone experienced this problem before?

Low Idle CO 2.76 vol% Above 0.30%

(751 грт ) An IS HC 74 ppm Above 0 ppm

High Idle Lambda: 0.91 Not between 0.97 and 1.03

( 2,700 грт ) CO 3.45 vol% Above 0.20 %

HC 69 ppm

[finetrond]

When the teat was done, was the engine up to full working temperature?
Others have been questioning the if the cars engine is cold when the test is done and this may influence the emissions.

[Alan1001]

Hi finetrond,

Thanks for the response, yeah I drove the car on the motorway in a low gear just before the test to heat it up.

[bigkris06]

You would expect those readings from an issue with the cat or one of the lambda sensors. As you have no fault codes that does probably eliminate that.
It could also be a sign of running rich (to much fuel to air) but again this is points to cat / lambda sensor.
What is your temp gauge showing? Is it running cold? That could also cause this sort of issue, if you have access to live data you can see exactly how hot the engine is running when up to temp. If it’s not hot enough it will affect the emissions as well.
How long have you had the car?
Could there be a possibility it has a decat and it has been coded out therefore not throwing a code?
If you have had a previous MOT with no issues this is unlikely.
Hope this helps