how to fix P0420 code in Toyota RAV4 XA40 (2013-2018) after replacing catalytic converter

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery negative terminal to prevent electrical shorts.
• Allow the exhaust system to cool before working on it to avoid burns.

2. Inspect and Verify Installation

• Tools Required: Socket set, torque wrench
• Inspect the catalytic converter installation:
  1. Ensure all bolts and clamps are tightened to the manufacturer's torque specifications (typically around 30-45 lb-ft for the exhaust system).
  2. Check for any visible gaps or leaks at the joints.
  3. Make sure the oxygen sensors are properly installed in their respective locations.

3. Test and Replace O2 Sensors (if necessary)

• Tools Required: O2 sensor socket, multimeter
• If the O2 sensors are faulty:
  1. Remove the downstream O2 sensor from the exhaust system.
  2. Use a multimeter to test the sensor's resistance and voltage output (should fluctuate between 0.1V to 0.9V).
  3. If the sensor is out of specs, replace it with a new one.
  4. Install the new sensor and reconnect the wiring harness.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• After making repairs:
  1. Reconnect the battery terminal.
  2. Use an OBD-II scanner to clear the P0420 code.
  3. Start the vehicle and take it for a test drive to monitor for any reoccurrence of the code.