check engine light code is p3008, what does that mean,how much to repair

I' AM INTERESTED BUYING A 2005 CADILLAC CTS, AND THE OWNER TOLD ME THAT THE CODE WAS P3008. I ALREADY QUESTIONED ONCE ABOUT IT BEING THE CORRECT CODE, AND SHE SAID YES. WHY DO YOU ASK?.

There is no such code for that car. Scan it yourself