I own a 1992 Cadillac Sedan Deville (4.9L, FWD). Recently, I have been having issues with it. The service engine light and service vehicle light randomly come on and off. When they come on, my speedometer displays nothing but "0" and I have issues accelerating. The acceleration issue seems like a brake is constantly held down or that I'm in a lower gear than I need to be in. I am not sure if the acceleration problem is actually either of those, but that is what it feels like to me. As I'm driving, those lights will switch back off after awhile and my vehicle drives fine, but never for long before the lights come back on. I have taken it to a few shops, but no one seems to have the right OBD-I chip to scan it. Any help or information on what may be wrong would be much appreciated.