I just bought another 1991 Previa last week. This is the second '91 in my "collection" and I was told by Toyota that was never taken in for the service campaigns. There are two on this model year- the expansion valve and the right windshield wiper arm. There were four others that I had looked at purchasing and three of them had already had the expansion valve taken care of but none had the wiper arm replaced. This makes me believe that most Previa owners are unaware that these campaigns even exist.