how to fix P0420 code in my Toyota Camry Seventh Generation (2012-2017)?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to avoid electrical shorts during repairs.

2. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench, penetrating oil
• Apply penetrating oil to the threads of the oxygen sensors to ease removal.
• Use the O2 sensor socket to remove the upstream and downstream oxygen sensors.
• Install new oxygen sensors and torque them to the manufacturer's specifications (typically around 30 lb-ft).
• Reconnect the wiring harness to both sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gasket, jack stands
• Raise the vehicle securely on jack stands.
• Locate the catalytic converter and inspect for physical damage or excessive carbon buildup.
• If replacement is needed, remove the bolts securing the catalytic converter to the exhaust system using a socket set.
• Remove any brackets or hangers supporting the catalytic converter.
• Install the new catalytic converter, ensuring proper alignment with exhaust ports and securing it with the original bolts or new hardware.
• Replace the exhaust gasket to prevent leaks and torque to manufacturer specifications.