1997 GPI error code

Can anyone help me with this code, PO171 System Lean Bank One. That is the code and what it means what do you check ? I changed gas cap and fuel filter. What else do I look for ? Has anyone else ever had this code ?

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Check the bank one O2 sensor for proper operation and go from there.
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Changed up stream of, light went out for about 40 miles, then back on.

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I changed o2 sensor and the light went out for about 40 miles. Then it came back on. Any more ideas on what to look for ?

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tinford46 wrote:

Vacuum leak, Exhaust leak, Injector problem as a start.
--
Steve W.
Near Cooperstown, New York
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