2001 siverado 5.3 code PO101 PO135 PO300

Sounds like a lean fuel condition-Check this components

1. Vacuum leaks

2. EGR and PCV valve.

3. Low fuel pressure.

4. Dirty fuel injectors.

5. Mass Air Flow Sensor.

6. Oxygen Sensor.

P0101: MAF sensor performance: Remove and clean. Carefully. Don't touch the sensor with your fingers. Use a towel or clean rag.
P0135: Heated O2 Sensor circuit, low voltage, Bank 1 sensor 1: Check the wiring and connection to this O2 sensor.
P0300: Engine misfire detected: Pull and replace plugs one by one to see which one causes the engine to run better. Determine problem. Check to ensure injector is pulsing. Make sure there is spark to the plug. Make sure the plug isn't overly worn, corroded, or contaminated with oil or carbon build up. Check compression.