how to fix P0420 code on my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.
• Raise the vehicle securely on jack stands if working underneath.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Remove the upstream (pre-catalytic converter) oxygen sensor:
  1. Locate the O2 sensor in the exhaust manifold or just downstream of it.
  2. Use the O2 sensor socket to unscrew the sensor.
  3. Inspect the sensor for damage or contamination.
• Install the new oxygen sensor:
  1. Apply anti-seize compound to the threads of the new sensor.
  2. Torque to the manufacturer's specifications (usually around 30-35 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Wrench set, socket set, exhaust hanger tool
• Remove the catalytic converter:
  1. Locate the catalytic converter in the exhaust system.
  2. Remove any bolts or nuts securing the converter using the socket set.
  3. Use the exhaust hanger tool to detach the converter from hangers.
• Install the new catalytic converter:
  1. Position the new converter and secure it with bolts/nuts to the exhaust.
  2. Ensure all connections are tight and properly aligned.

4. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature to monitor for any reoccurring issues.