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

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Disconnect the vehicle's battery to ensure safety during the repair process.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (before the catalytic converter) oxygen sensor:
  1. Locate the sensor near the exhaust manifold.
  2. Use an O2 sensor socket to unscrew and remove it.
  3. Compare the new sensor with the old one to ensure compatibility.
  4. Install the new sensor and torque it to the manufacturer’s specifications (typically around 30 ft-lbs).
• Repeat the process for the downstream (after the catalytic converter) oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary), gaskets.
• Remove the catalytic converter:
  1. Locate the catalytic converter in the exhaust system.
  2. Use a socket set to remove the bolts securing the catalytic converter.
  3. If necessary, use an exhaust pipe cutter to detach the converter from the exhaust system.
  4. Inspect the mounting surfaces for any damage or corrosion.
• Install the new catalytic converter:
  1. Position the new catalytic converter and secure it with bolts.
  2. Torque the bolts to the manufacturer's specifications (refer to the service manual for the specific torque value).
  3. Replace any gaskets to prevent leaks.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the error codes from the computer.