One problem related to tank filler pipe and cap has been reported for the 1998 Audi A4. The most recently reported issues are listed below.
Extreme difficultyfueling car - pump shuts off continuously and forumsseem to indicate that this is not an isolated problem abd has occurred with other cars. Have been to dealer and only advice is to replace fueld tank at a cost of some $2,000 - car has 45,000 miles.