Polo 6N rough idle / high CO level

Please provide the text you would like me to translate from German to English.

ATM --> new, used, or refurbished?

Let's start with the basics: valve timing, ignition timing.

Since the CO level is too high, it's running too rich.
That probably isn't a vacuum leak...

As Autoservice writes,
work through the basics.

I'm experiencing the same issue with my 'Erdbeerkörbchen' (strawberry basket) when the ignition timing is too late.