Volvo: 1993 240 wagon stalling problems, air flow sensor, oxygen sensor

Question
I purchased this car last summer after having owned a
1990 240 from new. A few months in and the car began
having trouble starting and running. Sereval trips to the
shop for various parts replacements (mainly snesors)
ending in an engine computer exchange. This cured the
starting problem, but then a month or so later, while
coming to a stop at a light the car just stopped. I had a
great deal of trouble restarting the car. It eventually did and
I drove home without further incident. No matter how many
times I take the car in, they are unable to locate the source
of this problem. It has begun to happen more regularly and
even when the car is in motion, I have begun to feel the
engine die. Being in motion it doesn't stop but seems to get
through the problem. Come to a full stop and the engine
dies completely.  

Answer
For problems where the engine runs on its own most of the time, but dies periodically, I tend to look for malfunctioning sensors, which sounds like what you did once already.  In your case, it sounds like you are running a bit rich, which can happen for several reasons.  I would check your oxygen sensor, the air flow sensor, as well as the knock sensor.  Finally, I would also check the condition of the throttle body.  They can get gunked up and cause the car to die periodically.  Good luck!