how to fix the P0420 code on my Genesis G70 IG (2017-2023)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the exhaust system to cool before working.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:

   • Disconnect the electrical connector.
   • Use an oxygen sensor socket to remove the sensor.
   • Tools Required: Oxygen sensor socket, wrench.

2. Install the new upstream oxygen sensor:

   • Apply anti-seize compound to the threads of the new sensor.
   • Thread the sensor into the exhaust manifold and tighten it to manufacturer's specifications (usually around 30 lb-ft).
   • Reconnect the electrical connector.

3. Repeat for the downstream oxygen sensor:

   • Follow the same steps as above for the downstream sensor located near the catalytic converter.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the catalytic converter:

   • Unbolt the exhaust pipes connected to the catalytic converter.
   • Remove any brackets or hangers supporting the converter.
   • Tools Required: Socket set, torque wrench.

2. Install the new catalytic converter:

   • Position the new converter in place and secure it with bolts.
   • Ensure proper alignment of the exhaust system and tighten bolts to the manufacturer's torque specifications.

3. Reinstall any removed components:

   • Reattach exhaust hangers and brackets.
   • Double-check connections for leaks.