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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Carefully disconnect the electrical connectors of both the upstream and downstream oxygen sensors.
• Remove the upstream O2 sensor using the O2 sensor socket.
• Install the new upstream O2 sensor, tightening it to the manufacturer’s specified torque (usually around 30 lb-ft).
• Repeat the process for the downstream O2 sensor if it is faulty or contaminated.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary), gasket scraper
• Remove any heat shields or components obstructing access to the catalytic converter.
• Unbolt the catalytic converter from the exhaust system using a socket set.
• Inspect the mating surfaces for any damage and clean if necessary.
• Install the new catalytic converter, ensuring all gaskets are replaced and bolts are tightened to the specified torque.

4. Reset the Engine Control Module (ECM)

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the ECM.