how to fix P0420 code on my Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety during the process.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Instructions:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Using the O2 sensor socket, carefully remove the upstream sensor first.
  3. Install the new upstream oxygen sensor and tighten it to the manufacturer’s torque specification (typically around 30 ft-lbs).
  4. Repeat the process for the downstream oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust gasket, exhaust clamp.
• Instructions:
  1. Safely lift the vehicle using a jack and secure it with jack stands.
  2. Disconnect the exhaust system at the flanges near the catalytic converter using the socket set.
  3. Remove any heat shields, if applicable, to access the catalytic converter.
  4. Carefully remove the catalytic converter from the exhaust system.
  5. Install the new catalytic converter with new gaskets and clamps to ensure a proper seal.
  6. Reattach any heat shields and reconnect the exhaust system.

4. Reconnect Battery and Clear Codes

• Reconnect the battery after all repairs are completed.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.