how to fix my Toyota RAV4 XA50 (2019-2024) check engine light and P0420 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure safety equipment is on hand (gloves, safety glasses).
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Use an O2 sensor socket to remove the sensors from their ports.
  3. Inspect the sensors for damage or contamination.
  4. If faulty, replace the sensors with new units (ensure compatibility with your vehicle).
  5. Reinstall the sensors and reconnect the wiring harness.

3. Check and Replace the Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust system components connected to the catalytic converter (e.g., heat shields, bolts).
  2. Use a ratchet and socket to carefully detach the catalytic converter.
  3. Inspect the old catalytic converter for physical damage or clogging.
  4. If replacement is required, install the new catalytic converter, ensuring proper alignment.
  5. Reattach any components removed in the disassembly process, tightening to manufacturer specifications.

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Start the engine and let it reach operating temperature.
  3. Use the OBD-II scanner to clear the P0420 code from the ECM.