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

Solution

1. Preparation

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

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench, multimeter.
• Remove the upstream O2 sensor (before the catalytic converter) using an O2 sensor socket.
  • Sub-steps:
    • Disconnect the electrical connector.
    • Use the O2 sensor socket to unscrew the sensor.
• Install the new O2 sensor and torque it to the manufacturer’s specifications (typically around 30 lb-ft).
• Repeat the process for the downstream O2 sensor (after the catalytic converter) if necessary.

3. Inspect and Replace Catalytic Converter (if required)

• Tools Required: Socket set, torque wrench, exhaust gasket.
• Locate the catalytic converter and inspect for any visible damage or blockages.
  • Sub-steps:
    • Remove any heat shields if present.
    • Use a socket set to unbolt the catalytic converter from the exhaust system.
• Install the new catalytic converter with new gaskets.
  • Sub-steps:
    • Align the converter and attach with bolts, ensuring proper fit.
    • Torque bolts to manufacturer specifications (typically around 25 lb-ft).
• Reinstall any heat shields removed during the process.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and perform a test drive to ensure the system operates correctly.