1998 Ford F150 2 codes P0171 and p0174

1998 FORD F-150
89,500 MILES • V8 • 2WD • AUTOMATIC
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LAFAN42
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  • 1 POST
I have replaced, spark plugs, MAF sensor (rebuilt), PVC valve, air filter, EGR sensor, fuel pressure regulator, fuel filter and tore the top of engine off looking for a vacuum leak to no avail. Each time we do something we clear the codes and they stay off for a few miles and then come right back on. Can anyone help?
Jun 4, 2010 at 1:46 PM
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RASMATAZ
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Hi LAFan42, Welcome to 2carpros and TY for the donation

Check the injectors and the fuel pressure you haven't done this two that can cause a lean fuel condition
Jun 4, 2010 at 4:44 PM
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