What does p0171 code on Santa Fe 2004?

The P0171 code on a 2004 Hyundai Santa Fe indicates that the engine control module (ECM) has detected a lean air-fuel mixture in the engine, meaning there's too much air or not enough fuel being supplied. This can be caused by issues such as a vacuum leak, a faulty mass airflow sensor, or fuel delivery problems. It's important to diagnose the underlying cause to prevent engine performance issues and potential damage. Addressing the P0171 code typically involves inspecting the air intake system, fuel injectors, and related sensors.