how to fix P0420 code on my Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the vehicle to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream oxygen sensor:
  1. Locate the upstream oxygen sensor on the exhaust manifold.
  2. Use the O2 sensor socket to unscrew and remove the sensor.
  3. Install the new sensor and torque to manufacturer's specification (typically 30 lb-ft).
• Repeat for the downstream oxygen sensor if testing indicates malfunction.

3. Inspect Catalytic Converter

• Tools Required: Wrench set, jack and jack stands, exhaust pipe cutter (if needed)
• Visually inspect the catalytic converter for signs of damage or excessive rust:
  1. Raise the vehicle and secure it on jack stands.
  2. Check for rattling sounds when tapping the converter, indicating internal failure.
  3. If damaged, cut out the old converter and install a new one.
• Replace with a direct-fit catalytic converter that meets OEM specifications.

4. Clear the Error Codes

• Tools Required: OBD-II scanner
• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.