yeah this is just an update so far of what ive done MECHANICALLY to my 1990 volvo 240 dl that i bought for several hundred bucks...it ran okay when i first bought it. this is wahat i ve ddone so far....at the volvo dealership...new timing belt, tensioner, and water pump....650...fuel pressure regulator and new fuel filter....250....new battery...70alignment....70....tahts it soo far..and just today...when coming back from the dealership....check engine light comes on....so ran back to volvo and they said its a bad o2 sensor...rpms were goin crazy and while driving down the interstate at 65 mph...my car shuts off..do u think its the o2 sensor that did it???...so thats going to be about 300. plus all of the misc. stuff i bought from the yard...floormats...tach/clock kit...new hubcaps...atennae...and other random stuff...came up about 60 bucks....this is INSANE how much i have to put into this car...so far ive put over 1800 dollars in to this car....idk how much more i can take. please give me some input thanks its much needed...my mom is really really upset cause we thought buyin this car would be good but so far its been at volvo 2 times a week...do u think this is just maintainence im doing or what.. thanks

I think you are making up for lack of maintance in the past.
Check the speed sensor for the stalling.