non-diesel engines stop for 3 reasons :
1. They broke something important internally.
2. they have no fuel.
3, they have no spark.

Next time it quits, see if it will crank over.
If it will, then unplug one of the plug wires at the coil pack and hold it close to the socket while trying to start. If you see spark, then you have a fuel problem. If not, then most likely a CPS connection or some other PTCM signal is bogus.

You can also see if fuel sprays out from the test port on the front of the fuel rail when you depress the Schrader valve. That will indicate you have fuel pressure.