my Skoda Octavia NFL (2020-Present) exhaust smells bad, what could be causing it?

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Locate the upstream and downstream oxygen sensors in the exhaust system.
• Use an O2 sensor socket to remove the faulty sensors.
• Install new oxygen sensors and tighten them to the manufacturer’s specifications (usually about 30-40 Nm).
• Reconnect the battery.

3. Replace the Catalytic Converter (if necessary)

• If the catalytic converter is damaged or clogged, it must be replaced.
• Disconnect the exhaust pipes from both ends of the catalytic converter using a socket set.
• Remove any mounting brackets and the old catalytic converter.
• Install the new catalytic converter and secure it with the appropriate hardware.
• Reconnect the exhaust pipes and ensure all connections are tight.

4. Address Fuel System Issues

• If fuel trim readings indicate a rich condition, check the fuel injectors for leaks or malfunctions.
• Replace any faulty fuel injectors with new ones, ensuring proper sealing and torque (typically around 15 Nm).
• Inspect and replace the air filter if clogged, ensuring unobstructed airflow to the engine.

5. Clear Codes and Test

• After repairs, clear any diagnostic trouble codes using the OBD-II scanner.
• Start the engine and allow it to reach normal operating temperature.