This means the air/fuel mixture in the engine's cylinders is too lean on Bank 1. Bank 1 refers to one side of the engine (usually the side containing cylinder #1). A lean mixture means there's too much air and not enough fuel.
Several things can cause this code:
* Mass Airflow Sensor (MAF) problems: A faulty MAF sensor can provide inaccurate readings, leading to a lean mixture.
* Vacuum leaks: Leaks in the intake system allow unmetered air to enter the engine, making the mixture lean.
* Fuel injector problems: A clogged or faulty fuel injector on Bank 1 can prevent sufficient fuel from being delivered.
* Fuel pump issues: A weak fuel pump may not be delivering enough fuel pressure.
* Fuel pressure regulator problems: A malfunctioning fuel pressure regulator can cause incorrect fuel pressure.
* Oxygen sensor problems: A faulty oxygen sensor (O2 sensor) may not be providing accurate readings to the engine control unit (ECU).
* EGR valve problems: Issues with the Exhaust Gas Recirculation valve can affect the air/fuel mixture.
To diagnose the problem, a mechanic will likely:
* Check for vacuum leaks: This usually involves a visual inspection and possibly a smoke test.
* Inspect the fuel injectors: They may be tested for proper operation and flow.
* Test the MAF sensor: Its reading will be compared to expected values.
* Check fuel pressure: A gauge will measure fuel pressure to ensure it's within specifications.
* Inspect and test the oxygen sensors: Their readings are checked for accuracy.
* Inspect and test the fuel pump: Checking output pressure.
Simply clearing the code won't fix the underlying problem. It's crucial to find and repair the root cause to prevent further engine damage and potential problems. A qualified mechanic should diagnose and repair the fault.
