why does my BMW 5 Series F10/F11 (2010-2017) exhaust smell like rotten eggs?

Solution

1. Preparation

• Gather necessary tools and replacement parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical issues.

2. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, jack and jack stands, O2 sensor socket, exhaust gasket.
• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Locate the catalytic converter in the exhaust system.
  3. Remove the O2 sensors from the catalytic converter using an O2 sensor socket.
  4. Detach the exhaust pipes connected to the catalytic converter using the socket set.
  5. Remove the catalytic converter from the vehicle.
  6. Clean the mating surfaces on the exhaust pipes and inspect for damage.
  7. Install the new catalytic converter, ensuring proper alignment and fit.
  8. Reattach the exhaust pipes and secure them with the appropriate torque specifications.
  9. Reinstall the O2 sensors and ensure they are connected properly.

3. Inspect and Clean the Fuel System

• Tools Required: Fuel pressure gauge, fuel injector cleaner.
• Sub-steps:
  1. Use a fuel pressure gauge to check the fuel pressure at the rail.
  2. If pressure is low, inspect and replace the fuel filter if necessary.
  3. Add fuel injector cleaner to the fuel tank as per the manufacturer's instructions.
  4. Run the engine to allow the cleaner to circulate through the injectors.