first of all im getting a code 44. i have changed the tb GASKET, removed the exhaust except the catalitic converter, cleaned the electric terminals and changed the O2 sensor. The truck will barley start and then dies after about 15 seconds uinlesss i spray starter fluid down the intake.. is this fuel pump , vac problem, fuel pump, or a combo of all three? It stsrted when i was going down the road and it stsrted to surge and i was able to nurse it back home by feathering the throttle. I thought bad gas, but addatives did nothing..any ideas?

CODE 44
Trouble Code 44 indicates that the O2 sensor is showing a persistently high exhaust oxygen content (lean), despite the efforts of the ECM to increase injector on-time (thus increasing fuel delivered). Integrator and BLM numbers may indicate > 128 by a substantial margin.

Typical causes for this code include:
1) O2 sensor defective or lead shorted
2) Lean injectors (dirty or blocked)
3) Water in fuel
4) Exhaust leaks upstream of O2 sensor
5) Fuel pressure or volume too low
6) MAF sensor reading lower airflow than is actually present
7) Vacuum leaks
8) Incorrect or poorly calibrated PROM