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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Safety glasses and gloves are recommended.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) O2 sensors.
2. Remove the O2 Sensors:
   • Use a wrench or O2 sensor socket to unscrew the sensors from the exhaust system.
3. Check the Sensor Condition:
   • Inspect for damage or contamination.
   • If faulty, replace with OEM sensors.
4. Install New Sensors:
   • Apply anti-seize compound to the threads (if required) and install the new sensors, tightening to manufacturers’ torque specifications (typically around 30 lb-ft).

3. Inspect and Replace the Catalytic Converter

1. Inspect the Catalytic Converter:
   • Visually check for physical damage, rattling noise, or excessive heat.
2. Remove the Catalytic Converter:
   • Disconnect the exhaust pipes using a socket set.
   • Unbolt the converter from the exhaust manifold and any mounting brackets.
3. Install the New Catalytic Converter:
   • Position the new converter and secure it with bolts, tightening to manufacturer specifications (typically around 30-40 lb-ft).
4. Reconnect Exhaust System: Ensure all connections are tight and leak-free.

4. Reset the Engine Control Module (ECM)

1. Reconnect the Battery: Attach the negative terminal back to the battery.
2. Clear Error Codes: Use the OBD-II scanner to clear the P0420 code from the ECM.