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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream (pre-catalytic) oxygen sensor by:
  1. Using the O2 sensor socket to unscrew it from the exhaust manifold.
  2. Installing the new oxygen sensor and tightening it to manufacturer specifications (typically 30-40 lb-ft).
• Repeat for the downstream (post-catalytic) oxygen sensor if it shows signs of failure.

3. Test and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust pipe cutter, exhaust clamps
• Raise the vehicle safely using jack stands to access the exhaust system.
• Remove any necessary heat shields or mounting brackets.
• Cut the exhaust pipe on both sides of the catalytic converter using an exhaust pipe cutter.
• Install the new catalytic converter:
  1. Align the new catalytic converter to the exhaust pipes.
  2. Secure with exhaust clamps and tighten to specifications.
• Reattach any heat shields or brackets previously removed.

4. Clear Codes and Reconnect Battery

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.