This means the engine's air/fuel mixture is too lean on bank 1 of the engine (typically the driver's side). A lean mixture has too much air and not enough fuel.
Several things can cause this:
* Vacuum Leaks: Leaks in the intake manifold, vacuum hoses, or other parts of the intake system allow excess air to enter, making the mixture lean. This is a very common cause.
* Mass Airflow Sensor (MAF) Problems: A faulty MAF sensor can provide inaccurate readings, leading to an incorrect air/fuel ratio.
* Fuel Injectors: Clogged or faulty fuel injectors can prevent the proper amount of fuel from being delivered.
* Fuel Pressure Regulator: A malfunctioning fuel pressure regulator may not maintain the correct fuel pressure.
* Oxygen Sensor (O2 Sensor): A bad O2 sensor can provide inaccurate feedback to the engine control unit (ECU), leading to a lean condition. Bank 1 refers to the oxygen sensor on the driver's side.
* Fuel Pump: A weak fuel pump might not deliver sufficient fuel pressure.
Troubleshooting Steps (in general, consult your repair manual for specifics):
1. Visual Inspection: Check all vacuum hoses and the intake manifold for cracks or leaks.
2. MAF Sensor Cleaning/Replacement: Clean the MAF sensor with MAF sensor cleaner (following instructions carefully). If cleaning doesn't solve the problem, it may need replacement.
3. Fuel Pressure Test: Check fuel pressure to ensure it's within specifications.
4. Fuel Injector Testing: This often requires specialized equipment.
5. O2 Sensor Testing: Testing the O2 sensor can determine if it's functioning correctly.
6. Fuel Pump Check: Test the fuel pump pressure and output.
Because multiple components can cause this code, a systematic approach to testing is crucial. If you're not comfortable performing these tests yourself, take your Silverado to a qualified mechanic for diagnosis and repair.
