what does the P0420 code mean for my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent any electrical issues during the repair process.

2. Inspect Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter, wrench set
• Remove the upstream and downstream oxygen sensors from the exhaust system.
• Use a multimeter to measure the output voltage of both sensors. The upstream should fluctuate between 0.1 to 0.9 volts, while the downstream should be relatively stable (0.4-0.6 volts).
• If either sensor is malfunctioning, replace it with a new one.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust gasket (if necessary)
• Remove the exhaust pipes connected to the catalytic converter using a socket set.
• Inspect the catalytic converter for physical damage or blockage.
• If damaged or blocked, replace it with an OEM or appropriate aftermarket catalytic converter.
• Reinstall the exhaust pipes and secure them with the correct torque specifications.

4. Clear Codes and Test

• Reconnect the battery and use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Take the vehicle for a test drive to ensure that the check engine light does not reappear.