1993 Cadillac Deville " Spring Edition " 74k original miles

Southern car absolutely no rus, no accidents, all original paint, All power options work including radio, ac works but could use a recharge, blows cool air but not super cold, excellent brake, recent oil change, air filter and new spark plugs, check engine light been on for 15 + years( mechanic ran code) power steering code but mechanic cant see or find a problem . Mechanic says not to worry about it. I have code written down. Mechanic looked over complete car and everything is in top working order. Runs beautiful and shifts great.