In 1991, Sullivan switched to the Patrick Racing Alfa Romeo team. After going winless in 1991 in a very uncompetitive machine, he parted ways with Patrick. Sullivan won two more CART races between 1992 and 1993, driving for Galles-Kraco Racing. He scored the first win for the Galmer chassis at Long Beach. It came after he bumped teammate and race leader Al Unser Jr. on the backstretch with less than four laps to go. The incident sparked friction within the team. His later years were plagued with inconsistency, leading to a semi-retirement in 1994. His brief tenure at Galles was described as particularly toxic.