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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:

   • Locate the upstream oxygen sensor before the catalytic converter.
   • Use an oxygen sensor socket and ratchet to unscrew the sensor.
   • Disconnect the electrical connector from the sensor.

2. Install the new upstream oxygen sensor:

   • Apply anti-seize compound on the threads of the new sensor.
   • Install and hand-tighten the oxygen sensor, then use the socket to tighten it to the manufacturer’s specifications.
   • Reconnect the electrical connector.

3. Repeat for the downstream oxygen sensor:

   • Locate and remove the downstream oxygen sensor using the same method as above.
   • Install the new sensor following the same steps.

3. Inspect and Replace the Catalytic Converter

1. Remove the catalytic converter:

   • Use a socket set to remove the bolts securing the catalytic converter to the exhaust manifold and the exhaust pipe.
   • Carefully detach the converter and inspect for any visible damage or clogging.

2. Install the new catalytic converter:

   • Position the new catalytic converter in place.
   • Secure it with the original bolts and use a torque wrench to tighten to manufacturer specifications (typically around 30-50 lb-ft, but check the service manual for specifics).
   • Ensure gaskets are replaced if necessary to prevent leaks.

4. Reset the Engine Control Module (ECM)

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code.
3. Start the engine and allow it to reach operating temperature.