I made the mistake of leaving something on in the cab of my 3500 8.1 Liter engine and the battery ran down. I charged the battery, but now the truck will start, but only runs for about 3 seconds, then shuts down. I put an analyzer on it and it give me a P0068 message about the MAF and MAP sensor and the throttle position, etc. I changed the MAF and the MAP, but still get an error code. It almost seems to be fuel pump issue, although I can hear the fuel pump turn on, I tried to put some gas into the air intake and it does run a little longer, also the fuel pressure seems to be low, as it does not spurt out vigorously, when I checked the pressure. It seems like gas should shoot out if it has 60 pounds of pressure. Do I need a new fuel pump? I am at a loss, any help would be very much appreciated. Do I need to reset the PCM . . . after replacing the MAF and MAP? Not sure what to do at this point, I can't seem to locate any vacuum tubes that are broken or cracked.