* Mass Airflow Sensor (MAF) issues: The MAF sensor measures the amount of air entering the engine. A faulty MAF sensor can provide inaccurate readings, leading to a lean condition. It might be dirty, damaged, or failing.
* Fuel injectors: Clogged or malfunctioning fuel injectors may not be delivering enough fuel to the cylinders.
* Fuel pump: A weak or failing fuel pump can't supply sufficient fuel pressure.
* Fuel pressure regulator: This component regulates fuel pressure; a malfunction can cause low pressure.
* Vacuum leaks: Leaks in the intake manifold or vacuum lines can allow excess air to enter the engine, creating a lean mixture.
* Oxygen sensor (O2 sensor): A faulty O2 sensor provides incorrect feedback to the engine control module (ECM), causing it to adjust the fuel mixture incorrectly. This is less likely to be the *cause* of a lean condition, but a bad sensor can prevent the ECM from correcting it.
* Improperly seated gas cap: A loose or damaged gas cap can allow air into the fuel tank, affecting the fuel system pressure. This is more likely to throw a related, but different, code.
To diagnose the problem accurately, you'll need to use an OBD-II scanner to get the specific trouble code(s) related to the "system too lean" message. The code will pinpoint the likely culprit. Then, you can:
* Inspect visually: Check for any obvious vacuum leaks, loose hoses, or damaged components.
* Test components: A mechanic can test the MAF sensor, fuel injectors, fuel pump pressure, and O2 sensors.
Ignoring a "system too lean" condition can lead to engine damage, including:
* Overheating: Lean mixtures burn hotter, increasing the risk of engine damage.
* Catalyst damage: Running lean can damage the catalytic converter.
* Reduced performance and fuel economy: The engine won't run as efficiently.
Don't attempt major repairs yourself unless you have the experience and tools. It's best to take your Silverado to a qualified mechanic for proper diagnosis and repair.
