Oh, please help if you can. My 98 Altima doesn't have check engine light on bug will intermittently stall when slowing to stop,idling, etc. Only does it on occassional trips. It is annoying! Took it to Nissan dealer, said no codes b/c check engine light is working but not on. Said he drove it for 22 miles and it acted fine. Right! Only advice, drive it until light comes on or perhaps sensor, converter problem, or computer. All are pricey and still don't know for sure which to throw parts out. Said during acceleration, seems sensor or computer is telling fuel mixture to become dense. Whatever that means. Please, if you can help narrow this down. I've changed to fuel filter, new spark plugs, air filter, basic tune-up but I just need to get this glitch fixed. Any suggestions would be appreciated.