The Code Reader takes common DTCs, breaks down when and why they occur and looks at symptoms and causes to help listeners make an accurate diagnosis.
The scan tool pulled a diagnostic trouble code of P0171: System Too Lean Bank 1.
P0171 has the same relevancy as P0174, which is “system too lean, bank 2.” The only difference is that a vehicle with an inline engine will only indicate P0171, and if the engine is a V- or opposed configuration, it can indicate either code, or both at the same time, depending on the cause of the problem.
When this code is stored it means that for some reason, and there’s a reason I say it like this, for some reason, too much air is present in the combustion process and the control unit is adjusting for the lean condition by adding fuel.
When the control unit has to correct for this condition for too long, it sets this code to alert you of the problem. This is important because in many cases there will not be a driveability symptom.