The exact cause can vary, but common culprits include:
* Mass Airflow Sensor (MAF) issues: A faulty MAF sensor can provide inaccurate readings, leading to a lean condition.
* Vacuum leaks: Leaks in the intake manifold or vacuum lines can draw in excess air, upsetting the air/fuel ratio.
* Fuel injectors: A clogged or malfunctioning fuel injector in bank 1 could reduce fuel delivery.
* Fuel pressure regulator: A problem with the fuel pressure regulator can lead to insufficient fuel pressure.
* Oxygen sensor(s): A faulty oxygen sensor (O2 sensor) in bank 1 can provide incorrect feedback to the PCM, resulting in a lean condition. There's a pre-cat and post-cat O2 sensor for each bank, either could be causing this.
* Fuel pump: In rare cases, a failing fuel pump could contribute to insufficient fuel delivery.
Important Note: This code is a symptom, not a diagnosis. You'll need to use a scan tool capable of reading live data (not just trouble codes) to further diagnose the problem. Observing live sensor data (MAF, O2 sensors, fuel trims) while the engine is running will help pinpoint the exact cause. Attempting repairs without proper diagnostic tools and knowledge could lead to further damage or unnecessary expense. It's recommended to take it to a qualified mechanic for diagnosis and repair.
