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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shocks.
• Allow the vehicle to cool if it has been running.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream (pre-catalytic) oxygen sensor:
  1. Locate the upstream O2 sensor near the engine on the exhaust manifold.
  2. Use the O2 sensor socket to unscrew the sensor from the exhaust pipe.
  3. Install the new O2 sensor and tighten it to the manufacturer's specified torque (usually around 30 lb-ft).
• Repeat for the downstream (post-catalytic) O2 sensor if it is also faulty.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool
• Remove the catalytic converter:
  1. Locate the catalytic converter, which is typically near the exhaust manifold.
  2. Disconnect any exhaust hangers and bolts connecting it to the exhaust system.
  3. Carefully remove the catalytic converter from its position.
• Install the new catalytic converter:
  1. Place the new catalytic converter in the same position as the old one.
  2. Reattach any exhaust hangers and bolts, tightening to manufacturer's specifications (usually around 40 lb-ft).

4. Reset the ECU

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0420 trouble code from the vehicle’s memory.