what does error code P0420 mean for my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:

   • Locate the sensor, typically near the exhaust manifold.
   • Use an oxygen sensor socket to unscrew the sensor.
   • Disconnect the electrical connector.

2. Install the new upstream oxygen sensor:

   • Apply anti-seize compound to the threads of the new sensor.
   • Screw it into place and connect the electrical connector.

3. Repeat for the downstream oxygen sensor if necessary:

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

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the catalytic converter:

   • Disconnect exhaust hangers and bolts attaching it to the exhaust system.
   • Remove any heat shields if present.

2. Install the new catalytic converter:

   • Position the new converter and secure it with the original or new mounting hardware.
   • Reattach exhaust hangers and heat shields as needed.

4. Clear Error Codes

• Use the OBD-II scanner to clear any error codes from the vehicle’s memory after repairs are completed.

5. Reconnect Battery

• Reconnect the negative battery terminal.