Lugging all the time in high gear at low RPM's

[Tm775]

Hey, as it says in the title, my tiptronic 2001 allroad as been lugging at any time when the gear is high and the rpm's are low, not just when going up hills but any any time. I checked the CAT's and they all seem to be fine and am wondering if there is anything else that could cause this stress on the engine??

[area51zc]

I had some lugging, replaced the sparkplugs and it went away, I think one of the spark plugs was randomingly shorting out and it was way more noticable at high gear low rpms and on take off.

Rob