1993 Buick Lesabre 180253 miles V6 engine, trouble code 42, will crank but will not start, no spark.

Three weeks ago I replaced the O2 sensor on the car took it for test run, ran great for 20miles then engine stalled. would not start for about 20min after which I was able to get it started again, I got home checked it out could find nothing wrong other then a trouble code 42 which had always popped up for the past year. after that one stall the car ran fine for two weeks no problems then last week it started to stall out four times in one day with it not starting again after the fourth stall. yesterday I replaced the crankshaft sensor and got it to start and run for about 60 seconds then it died and I haven't been able to start it since. so as of today I get no spark I still get  code 42 also the fuel does work I do get gas. I can use any help or advise you can give me since I live out in the desert and this is my only transportation. thank you