Goated with the sauce refers to the acronym G.O.A.T, (Greatest of all time), and with the sauce implies completeness. To be Goated with the sauce is to reach nirvana.
A somewhat inappropriate act popularized in Britain during the mid to late 1700's in which the crotch of a family member is playfully grabbed by a fellow family member.
Dad: Goitcha!
*Dad proceeds to grab his daughter's crotch*
Daughter: DAD! Stop it with the goitcha already!