Engine Performance problem
1999 Chevy Silverado 6 cyl Two Wheel Drive Automatic 115000 miles
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Gentlemen,I have a v6- 99 silverado. When I drive for a while and shut it off, when I restart it and go it backfires in the engine and has no power than its ok. Also if I push down hard on the gas it stumbles upon acceleration. I have replaced the fuel pump,fuel filter,plugs,wires distributer cap and both up stream o2 sensors and I still have this problem. The check engine soon light comes on some times but after a few restarts goes off. I pulled the following codes out of the computer, Po171 PoI174 which is a lean fuel system. I am at a loss. please help. Thanks guys!