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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Temperature gun
• Jack and jack stands or ramps

2. Inspect and Replace Oxygen Sensors

• Sub-step 1: Remove the oxygen sensor before the catalytic converter by disconnecting the electrical connector and using a socket to unscrew it.
• Sub-step 2: Install a new oxygen sensor, ensuring it is torqued to manufacturer's specifications (usually around 30 lb-ft).
• Sub-step 3: Repeat the process for the oxygen sensor after the catalytic converter if needed.

3. Inspect and Replace Catalytic Converter

• Sub-step 1: Remove any heat shields and exhaust components that obstruct access to the catalytic converter.
• Sub-step 2: Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe, using a socket set.
• Sub-step 3: Inspect the mounting surfaces for damage and clean if necessary.
• Sub-step 4: Install the new catalytic converter, ensuring it is aligned correctly, and tighten bolts to the specified torque (usually around 25 lb-ft).
• Sub-step 5: Reinstall any heat shields or components removed during the process.

4. Reconnect Battery and Clear Codes

• Sub-step 1: Reconnect the battery terminals and ensure they are tight.
• Sub-step 2: Use the OBD-II scanner to clear any trouble codes from the system.