When I purchased it in November of 2004, I did a complete PM on it. From Interior and Exterior Detailing, down to Wires, Plugs, All filters (except trans service), New loaded calipers with rotors, and a thorough cleaning and adustment of rear brakes, belts.
Disconnected battery terminal as suggested, I can hear a distinct "tone" change, so I believe that may have cured the problem...we will see on next fill up or two. But damn if the radio now doesn't work..LOC...I am the second owner of car...no codes left for me. My 93 SSE didn't have this AntiTheft portion on it so I never even thought to pull codes first. So this correction fixed a computer problem but expedited the non-working CD Player/Working Radio replacement sooner than I wanted to...for a remaned OEM one. No tunes for a week while another is in route.
Careful with the advice guys.....could have cost me more to have the dealer unlock it.