Oldsmobile Forum - Oldsmobile Enthusiasts Forums - 95 Olds 98 Regency Elite Stalling Repeatedly. Help!

Car runs fine 15+ minutes...then dies (no brakes, no steering, no digital speedometer or guages; entire dash goes dark). When this happens a message appears "HOT... AC Disabled". Feels like electrical failure. Park car or put in neutral; car starts immediately perfectly. Runs 5 minutes, Stalls again, exactly like before; restart in neutral again. At this point car stalls every minute or less. [Same stalling pattern every time I drive it.] I tried replacing ignition coils, they were clean; no improvement with new ones.

Took car to general auto mechanic, scanned; came up with "02 sensor" and "Intermittent plug firing". Replaced ICM, no improvement.

Took car to auto-electric specialist who did the following:

"Scanned engine control computer, check engine light is on. Accessed computer link. Programmed scanner to vehicle outputs. Performed scan of computer for trouble codes set in memory. Also ran live data scan where possible. Found codes po 135 o2 heater malfunction, po171 lean condition and vats key invalid. Checked lean condition. Test and found vacuum hose to purge solenoid off, causing vacuum leak and fuel trim out of range. Found oil gas-soaked. Rep'd air hose, drain and filled oil, replaced filter, cleared codes and reset fuel trim, run and checked o2 cross count range, range now within spec + or - 128. Found engine still stalls and knock sensor shows intermittent on scanner, removed connector and put engine in base timing mode and now engine does not stall. Found service bulletin on stall, checked PROM ID and found original equipment in place. Installed updated PROM. Stalls again. Checking intermittent stall. Tested all ignition circuits from crank sensor/cam sensor to ic mod; ig bypass and est circuits to ecm. Performed current ramping on fuel injectors. ICM had been replaced 2 years ago; tried substituting identical ICM; same results."

Please advise!