how do I fix the P0420 code on my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the exhaust system to cool before working on it.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, dielectric grease.
• Remove the upstream (pre-catalytic converter) oxygen sensor using the O2 sensor socket.
• Inspect the sensor for damage or contamination; replace if necessary.
• Apply dielectric grease to the sensor threads and install it securely.
• Repeat for the downstream (post-catalytic converter) oxygen sensor if needed.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting tool (if needed), exhaust gasket.
• Unbolt the catalytic converter from the exhaust pipes using a socket set.
• Inspect the catalytic converter for physical damage or clogging; replace if necessary.
• Install the new catalytic converter with a new exhaust gasket and torque the bolts to manufacturer specifications.
• Ensure all connections are secure and there are no leaks.

4. Reset Engine Control Module (ECM)

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0420 code from the ECM.
• Perform a short test drive to ensure the check engine light does not return.