how to fix P0303 code on Porsche Cayenne E3 (2018-Present)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Porsche Cayenne E3. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, noid light, multimeter.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Locate the ignition coil on cylinder 3 (refer to the owner's manual for cylinder layout).
  3. Disconnect the electrical connector from the ignition coil.
  4. Remove the ignition coil using a socket wrench.
  5. Unscrew the spark plug from cylinder 3 using the appropriate socket.
  6. Inspect the spark plug for wear (check gap and condition). Replace if necessary with a new spark plug (specify type as per manufacturer recommendation).
  7. Reinstall the new spark plug, tightening to the manufacturer’s specified torque (usually around 15-20 Nm).
  8. Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Fuel Injector (if applicable)

• Sub-steps:
  1. If the injector is suspected to be faulty, disconnect the fuel line and electrical connector from the fuel injector on cylinder 3.
  2. Remove the fuel injector using a socket or wrench.
  3. Install the new fuel injector, ensuring it seats properly.
  4. Reconnect the fuel line and the electrical connector.

4. Conduct Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 3.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine a few times and record the compression reading.
  4. Compare the reading with the manufacturer’s specifications. If low, further diagnosis may be required for internal engine issues.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear any error codes.