WORKING ON A '96 NISSAN MAXIMA GLE. WHAT'S THE MINIMUM FUEL OCTANE RATING? CAR STALLS WHEN SELECTING DRIVE TO REVERSE. HESISTATION WHEN ACCELERATING. RECENT SERVICE IN LAST (6) MONTHS TO INCLUDE: PLUGS REPLACED, FUEL FILTER REPLACED. ANY HELP OR SUGGESTIONS ARE GREATLY APPRECIATED. THANKS, 320i