On October 15, 2005 we had our prius serviced at Jon Lancaster Toyota like we have since buying the car in 2001 The first part November The check engine lite came on, we took the car into lancasters service department. Well the service manger came after us to show us the Air, and air condisioner filters where plugged and gritty Marked off on service check off on the prior service as good, they also rotated the tires and one showed the tread seperating from casing also checked as ok with the tire rotation.then less than an a month before.