V6 weaknesses?

[Tom Nas]

Hi all,

A friend of mine, one-time type 89 owner, has finally responded to my 
ongoing Audi indoctrination and is looking to buy a B4 80 Avant with the 
12v V6 ('95-on).
I've read some horror stories about plugged cats, busted head gaskets and 
leaking valley pans. Anything else to look for? What can you expect in the 
way of fuel economy (if that's a good term here...)?

Please all, help me get another friend back into Audi ownership...

Thanks, Tom
The Netherlands