stalling/system too lean
 

I have a 2000 silverado 2500 6.0 v8 154000 miles which is killing itself shortly after starting. It began as a rough idle a week or two later it quit on me. I have cleaned the throttle body, the maf sensor, the egr valve, checked the fuel filter, and so far no luck. diagnostic scan gave p0131 - O2 sensor low volts bank 1 sensor 1, p0137 - O2 sensor low volts bank 1 sensor 2, p0171 - System too lean bank 1, p0174 system too lean bank 2, and p0405 - EGR flow sensor A circuit low input. Thinking maybe a vacuum leak? any ideas?

check the fuel pressure. Everything but the egr flow code can be caused by low fuel pressure.

How did you check the fuel filter?

i checked the fuel filter by the steps shown ath this sight How to Check a Fuel Filter | eHow.com. I'm guessing what ever is causing the egr code to trip is also causing the rest of the codes?

thats somewhat of a volume check but that article is pretty dated. I usually pull the filter completely off and blow through it, if it takes any kind of effort to blow through it needs replaced

looking at the codes i'd lean towards either a vacuum leak or egr problem but checking fuel pressure is always the first step when theres lean codes or stalling