p0171 and p0174 issue

[03l300]

i got a 2003 saturn L300 with 110,000 on it i keep on getting these codes which is p0171: system to lean bank 1 and p0174: system too lean bank 2. does any one know what can be the problem?
i replaced a hose by the gas tank. i checked the air filter its good. i cleaned the MAF sensor. i replaces the gas cap. also a car with a wrench will come on and when its on the car will jerk.

[fdryer]

Both error codes have something in common. If you have a reader, monitor and record all data and post them. The service manual describes possibilities;

• A skewed mass air flow (MAF) sensor may set this DTC. Refer to DTC P0101 .
• The system will go lean if an injector is not suppling enough fuel.
• The system will go lean during high fuel demand.
• An EGR valve stuck open may set this DTC.
• A skewed engine coolant temperature (ECT) sensor may set this DTC.
• Review the Failure Records with a scan tool. If an intermittent condition is suspected, refer to Fuel Injector Coil Test .