how to fix P0301 misfire code in GMC Sierra T1XX (2019-Present)

Learn how to diagnose and fix P0301 cylinder 1 misfire in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the engine is cool and disconnect the battery to prevent electrical shock.

2. Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench.
• Sub-steps:
  1. Locate cylinder 1 spark plug (typically on the front of the engine).
  2. Remove the ignition coil by unbolting it and disconnecting the electrical connector.
  3. Remove the spark plug using a spark plug socket.
  4. Check the gap on the new spark plug and adjust to manufacturer specifications.
  5. Install the new spark plug and torque it to the specified value (usually around 13-15 lb-ft).
  6. Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• Tools Required: Socket set, torque wrench.
• Sub-steps:
  1. If the ignition coil is faulty, unbolt and remove it from the engine.
  2. Install the new ignition coil and torque it to the manufacturer's specification.
  3. Reconnect the electrical connector to the ignition coil.

4. Clean or Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector cleaner kit or replacement injector.
• Sub-steps:
  1. Disconnect the fuel line and electrical connector from the fuel injector.
  2. Remove the fuel injector from the rail.
  3. Clean the injector with a cleaning kit or replace it with a new one.
  4. Reinstall the injector and reconnect the fuel line and electrical connector.

5. Reassemble and Connect Battery

• Reconnect the battery terminals.
• Ensure all tools are removed from the engine bay.