P0171 Fuel Trim System Lean Bank 1,

whats this mean? I changed my fuel filter/regulator and then this came up. Im not sure what it means anyone know?

 

Start by checking your 02 sensors...its basically saying a lean air fuel mixture has been detected so its dumping much more fuel into the mixture to correct the lean A/F mixture.

 

hm, im only getting 9 psi when i hooked up a gauge to the end of my fuel rail. For my year, 2000, im supposed to be getting 44-54 psi, for newer 54-63. so I dont think its dumping too much gas because theres not alot of pressure in my system. I changed the Fuel filter today so i ordered the pump today since nothing changed, well i did get 1 more psi (9 vs 8) but nothing big. I can hear the pump kick on but I think its failing. I'll check my O2 sensor tmrw just in case, so it doesnt cost me 200 bucks. thanks man