Mechanic Q: 83 Cadillac Coupe Deville codes 4.8.8 & 0.7?

when I press the Warmer and off buttons 4.8.8 and then 0.7 comes up and the Service Soon and Service Now lights come on. I been having trouble with my car stalling after driving for a while, it will lose RPMs and if I let up on accelerator then press down on it sometimes it will continue to drive, other times it will stall and I have to wait to get it to start up again. Please can someone tell me what could be wrong?

Mechanic Q: car stalls?

My 83 coupe de ville stalls when driving extended period of time, and sometimes the trans seems to shift hard. The car when driving seems to all of a sudden loose rpms and sometimes stalls and I have to wait like 15 mins to start it up again, then drive a little more and it does it again. when I pushed the warmer and off buttons on the climate control 4.8.8 comes up then 0.7 comes up and just flashes 0.7 . what can be wrong ?