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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate and remove the upstream (pre-catalytic converter) oxygen sensor.
     • Disconnect the electrical connector.
     • Use the O2 sensor socket to unscrew the sensor.
  2. Install the new upstream oxygen sensor.
     • Apply anti-seize compound to the threads of the new sensor.
     • Torque to manufacturer specifications (typically around 30 lb-ft).
  3. Repeat the process for the downstream (post-catalytic converter) oxygen sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if applicable)
• Sub-steps:
  1. Remove the exhaust pipes connected to the catalytic converter.
     • Use a socket set to unbolt the flange connections.
     • If necessary, cut the exhaust pipe using an exhaust pipe cutter.
  2. Remove the catalytic converter from its mounting bracket.
     • Unbolt any additional mounting points.
  3. Install the new catalytic converter.
     • Position the new converter and bolt it securely to the mounting brackets.
     • Reconnect the exhaust pipes and tighten all bolts to the specified torque.
  4. Reconnect any sensors or components removed during the process.