Will start but won't stay running. Please help!!
 

I have a 2005 neon and without any warning it just won't stay running. It will crank go up to 1000 rpm and then die. I had a friend come look at it and he checked the alternator, battery, fuel pump. He seems to think it's one of the sensors, but I have no idea which one to start with. Any help would be greatly appreciated. I'm a single mother and this is my only means of transportation. Thank you in advance.

Check engine light on? Full of gas? What engine? How many miles? Last tune up? Need more information.

Gas tank is full. It has 160k miles. Just had a tune up in March. It's a 2.0

Check engine light on? Had it scanned for stored codes? If it's a sensor, there will be a code.