Not intended as legal advice: Section 24007 (b)(2) of the Vehicle Code states it is the responsibility of the seller to provide a valid smog certificate at the time of delivery of the vehicle. There is no provision in the law to sell a vehicle "as is". In this specific case the courts might rule that the sale of this vehicle is invalid and order you to return the buyer's money and accept your vehicle back. A judge may or may not rule as such. As we are not attorneys, it be best to consult one; preferably which has experience in vehicle sales. As-is sales are done everyday, with and without smog certificates. Most sellers and/or buyers are unaware of this vehicle code section. It is not typical for law enforcement to charge a vehicle's seller with violating CVC 24007 (b)(2); a court's ruling however might be different.