Possible causes for this code include:
* Vacuum Leaks: Leaks in the intake manifold, vacuum hoses, or PCV system can allow excess air to enter the engine, leading to a lean condition. This is a very common cause.
* Mass Airflow Sensor (MAF) Issues: A faulty MAF sensor can provide inaccurate readings, causing the engine to receive less fuel than needed.
* Fuel Injectors: Clogged or malfunctioning fuel injectors in Bank 2 can prevent sufficient fuel delivery.
* Fuel Pump: A weak fuel pump might not be providing enough fuel pressure.
* Fuel Pressure Regulator: A malfunctioning fuel pressure regulator could be causing low fuel pressure.
* Oxygen Sensor (O2 Sensor): A faulty O2 sensor in Bank 2 may not accurately report the air/fuel ratio, leading to incorrect fuel delivery.
* EGR Valve: A malfunctioning EGR (exhaust gas recirculation) valve can affect the air/fuel mixture.
Troubleshooting steps:
Before replacing any parts, it's crucial to properly diagnose the issue. Here's a suggested order:
1. Visual Inspection: Carefully check all vacuum hoses and the intake manifold for cracks, leaks, or loose connections.
2. MAF Sensor Check: Have the MAF sensor tested or replaced if faulty. A dirty sensor can also be a problem; cleaning it might resolve the issue.
3. Fuel Pressure Test: Test the fuel pressure to ensure it's within specifications.
4. Fuel Injector Test: Test the fuel injectors in Bank 2 to check for proper operation. This usually requires specialized tools.
5. O2 Sensor Test: Check the O2 sensor in Bank 2 for proper operation and signal voltage. This also usually requires a scan tool.
Important Note: Bank 2 refers to the side of the engine that *doesn't* contain cylinder #1. Consult your owner's manual or a repair manual specific to your 2001 Chevy Silverado to identify which cylinders are in Bank 2. A misdiagnosis could lead to unnecessary part replacements. It's often best to take your vehicle to a qualified mechanic for proper diagnosis and repair.
