Here is a suggestion: Yes a bad cat can cause it to stall.......
Either of these parts can break apart internally and cause a temporary blockage of the
exhaust system causing the engine to stall. To check for this condition start with the engine cold, then take a rubber mallet and hit the muffler and catalytic converter. There should be very little rattling sound when struck with the hammer. If you can hear what sound like rocks inside your exhaust system, remove it and inspect it for internal damage.

 

Maybe, place some flex pipe where the cat converter is and see how it runs....

FYI: I picked up the above info from
http://www.2carpros.com/articles/eng...-while-driving

Check that web site... Also, consider if you have an automatic trans that the torque converter can cause this.

 

Give the ignition key a jiggling see if the switch is the cause...

 

eh its possible

 

My 98 silverado 5.7 Vortec was stalling, finally died dead on the side of the road. It turned out to be the crankshaft positioning sensor.

 

Fuel pressure regulator guaranteed