Car runs great drive it between 17/20 miles and it will just shut off! car has 53000 miles and is a beast? changed all sensors, fuel pump totatly lost?once in a blue moon it will backfire through the exhaust?

have you replaced the egr valve

Try changing or switching out the distributor. Most likely getting hot and shuts down. Does it crank but no start whenever it stops? May only start when it cools down again.

Fuel Pump?

Might want to check timing. The chain and timing gears might need to be changed.

Have you had the vehicle hooked to a diagnostic scanner ? Check the ASD relay ? - auto shut down relay . Relay's do go bad . The ASD relay on your vehicle power's fuel pump , ignition coils ,fuel injector's ,O2 sensor heaters etc...

it sounds like fuel pump may be overheating, cools down and work again...i'am sure you changed the fuel filter??? hope this helps you??

This could be a couple different things . did they test ur fuel pressure? Cause a lean code would be that the vehicle is not getting enough gas. The fuel pump may be going bad. A lean code for the o2 sensor doesnt always mean a o2 problem it also can mean fuel problems.

On the 1999 - 2000 5.7 vortec engines the distributor gears wear causing the timing to change 2 or more degrees. The ecm is designed to shut down at 2 or more degreedifference. This is in a GM bulletin that recommends replacement at 160k miles. Mine went out at 150k miles. Very similar driving symtoms until it quit running. Both cam sensor codes were set on mine though, not the crank sensor.

Check first your crank sensor.
Make scanner for engine and transmission.
Check your air filter.
Check fuel filter

It is a possibilty that the fuel pump is malfunctioning, it is also a possibility the the fuel injectors are clogged, and need cleaning or that the cylinder valves are crusted with soot, and are causing a backdraft of exhaust to enter the cylinder chamber. Try using a fuel additive that cleans these parts on a regular basis (I do it every week despite the instructions for once every 1000 miles) and see if this helps the problem.