how to diagnose P0420 code on Toyota Camry Seventh Generation (2012-2017)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery cable.
• Allow the vehicle to cool down.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Remove Oxygen Sensors: Use an oxygen sensor socket to carefully unscrew and remove the sensors.
3. Install New Oxygen Sensors: Apply anti-seize compound to the threads of the new sensors and install them, tightening to manufacturer specifications (typically around 30 ft-lbs).
4. Reconnect Electrical Connectors: Ensure all electrical connectors are securely attached.

3. Inspect and Replace Catalytic Converter

1. Remove Exhaust Components: If the catalytic converter needs replacement, unbolt any exhaust components connected to it using a socket set.
2. Inspect Mounting and Gaskets: Check for any damaged gaskets or exhaust hangers and replace them if necessary.
3. Install New Catalytic Converter: Position the new catalytic converter and secure it with the appropriate bolts and gaskets, torquing to manufacturer specifications (typically around 30-50 ft-lbs).
4. Reassemble Exhaust System: Reattach any previously removed exhaust components ensuring all connections are tight.

4. Final Checks

1. Reconnect Battery: Reconnect the negative battery cable.
2. Clear Error Codes: Use the OBD-II scanner to clear any stored error codes.
3. Test Drive the Vehicle: Drive the car for a short distance to ensure that the check engine light does not reappear.