What's wrong with my Ford Focus? It turns off at every stop! A mechanic checked his comp and said no errors

It just turns off. A friend changed my burnt sparkler cables, my spark plugs, my fuel filter and other stuff, but he can't seem to find what's wrong with it. Is there something else wrong with it? When a mechanic hooked it up to a comp to check to see what's wrong with it, nothing came up since the check engine light isn't on. What's up with the car? It's a 2000 Ford Focus SE.

Keys going in, key cylinder won't turn… Tap on the key while trying to turn it and get it to a ford dealer… They have had issues with the key clyinders and there's a new one out to fix that problem.

Mechanics don't just hook up an OBD II code reader. They have a $2500 scan tool that reads the engine data to make sure all of the sensors are working with in spec. The first thing to do is clean the throttle body and then use the scan tool to make sure that the idle air control motor is not bad. That's what controls the idle speed. Go to the dealer if you don't know how to find a real mechanic!

I know on older cars there was a step down on the accelerator cable so when stopping of slowing it would close slowly to prevent stalling

Faulty fuel pump and or fuel injection system!