Check engine light is on all the sudden and I started to notice a slight idle along with it not taking off as fast as it usually does . I got a diagnosis and they said Bad Spark plug I am wondering if that could cause the other issues

What is your question?

I notice that the check engine light when first starting is off until I turn car back on again . I just don't know Much mechanical not only trust them to not have been the issue and it be more severe

What makes this problem better or worse?

It just started to do this 2 Days ago

How long has your 2002 Audi A6 Quattro had this problem?

4 Days engine light 1 day the sluggish and the slight idle