What is the meaning of OBD-II code P0171, and what are the possible causes and solutions for this code to be generated?

OBD-II code P0171 refers to a lean condition in the engine's fuel system. A lean condition occurs when there is not enough fuel in the air-fuel mixture and too much air. The Engine Control Module (ECM) detects this condition through the oxygen sensor and generates the P0171 code. There are several possible causes for a lean condition and the P0171 code to be generated, such as: -A vacuum leak in the intake system -A clogged air filter -A malfunctioning mass air flow sensor -A malfunctioning fuel pressure regulator -A malfunctioning injector -A malfunctioning oxygen sensor -A problem with the engine's compression. To diagnose and fix the problem, a mechanic will typically use a scan tool to retrieve the stored diagnostic trouble codes and perform a visual inspection of the vehicle's intake system, fuel system, and vacuum hoses. They may also check the compression of the engine and the fuel pressure. Depending on the cause of the code, the solution may involve fixing a vacuum leak, replacing a clogged air filter, replacing a malfunctioning sensor, repairing or replacing a malfunctioning injector, or replacing a malfunctioning oxygen sensor. In some cases, the problem may be caused by a more serious issue with the engine, such as a faulty cylinder head or a blown head gasket. It's important to note that a lean code can also be caused by a problem with the engine control module programming, so in some cases, a software update may be necessary to fix the issue.