how to fix P0420 code on my Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Raise the vehicle using jack stands and secure it.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor (pre-catalytic converter) by:
  1. Locating the sensor on the exhaust manifold or pipe.
  2. Using the O2 sensor socket, unscrew and remove the sensor.
  3. Install the new oxygen sensor, tightening it to manufacturer specifications (typically around 30 ft-lbs).
• Repeat the process for the downstream oxygen sensor (post-catalytic converter) if it shows signs of malfunction.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust gasket.
• If the catalytic converter is suspected to be faulty:
  1. Remove the exhaust pipe connected to the catalytic converter by loosening the bolts/nuts.
  2. Unbolt the catalytic converter from its mounting points.
  3. Install the new catalytic converter, ensuring to replace any gaskets and tighten bolts to manufacturer specifications (usually around 30-40 ft-lbs).

4. Clear Error Codes

• Reconnect the battery and use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and check for any reoccurrence of the code.