1997 Pontiac Bonneville SSE, 118000 mi, it happens twice within a week, engin stalls when I stoped at red light, check engin light come up and I could not start the car right away. First time there were 6 g of gas in the fuel tank, I added 3 g more and it starts like nothing happen. Second time with 3/4 tank of gas heppens exectly the same, I swing the car up and down several times (thinking that some thing wrong inside the fuel tank) then start the engin like nothing happen ???
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
I have a 1996 Bonneville with the exact same problem. It happens only when I have been doing a lot of in town driving; you know, when I run here and run there, usually short distances. I will be driving to the nearest city tomorrow, so will probably happen again, so I can get a reading from Autozone or Advanced and post my code.