It is illegal in California to sell a car without a current smog certificate. This is the seller's responsibility, not the buyer's. If the vehicle does not have such a certificate, you should be able to return the car and get your money back. If you would like to consult further on this matter, feel free to contact me at my office number, which is 800-517-2877.
Disclaimer: The information provided in this answer is for information only and does not constitute legal advice, nor does it create an attorney-client relationship.