how to fix P0302 misfire code on my Volkswagen Passat B8 (2015-2022)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug and Ignition Coil (if faulty)

• Tools Required: Socket set, torque wrench, ratchet, spark plug socket.
• Sub-steps:
  1. Remove the engine cover (if applicable) by unscrewing the bolts.
  2. Locate the ignition coil on cylinder 2.
  3. Disconnect the electrical connector from the ignition coil.
  4. Remove the ignition coil by unscrewing it from the cylinder head.
  5. Remove the spark plug using a spark plug socket.
  6. Inspect the old spark plug for wear; replace it with a new spark plug (ensure proper gap as per manufacturer's specifications).
  7. Install the new ignition coil and ensure it is securely fastened.
  8. Reconnect the electrical connector to the ignition coil.

3. Test Fuel Injector

• Tools Required: Noid light, multimeter.
• Sub-steps:
  1. Disconnect the electrical connector from the fuel injector of cylinder 2.
  2. Use a noid light to check for proper signal; if the light does not flash, there may be an issue with the wiring or the ECU.
  3. If the noid light verifies an electrical signal, use a multimeter to check the resistance of the injector. Refer to manufacturer's specifications for acceptable resistance values.
  4. Replace the injector if it is faulty.

4. Conduct Compression Test

• Tools Required: Compression gauge.
• Sub-steps:
  1. Remove all spark plugs to allow for easier cranking.
  2. Insert the compression gauge into the spark plug hole of cylinder 2.
  3. Crank the engine for a few seconds and note the reading. Compare it to specifications for normal compression.
  4. If compression is low, inspect for potential mechanical failures (valves, piston rings).

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Sub-steps:
  1. Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine to introduce smoke into the intake system; observe for smoke escaping, indicating a leak.
  3. If a leak is found, replace the damaged hoses or repair the intake manifold as necessary.