how to fix P0420 code in Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

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

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Safety glasses
• Gloves

2. Inspect and Replace Oxygen Sensors

• Sub-step 1: Remove the upstream oxygen sensor using a socket wrench.
• Sub-step 2: Install the new upstream oxygen sensor and torque it to manufacturer specifications (usually around 30 ft-lbs).
• Sub-step 3: Repeat the process for the downstream oxygen sensor if it shows signs of failure or if the replacement is warranted.

3. Inspect and Replace Catalytic Converter

• Sub-step 1: Safely raise the vehicle and secure it on jack stands.
• Sub-step 2: Unbolt the catalytic converter from the exhaust system using a socket set.
• Sub-step 3: Remove the old catalytic converter and inspect the exhaust pipes for any obstructions.
• Sub-step 4: Install the new catalytic converter, ensuring proper alignment and torque the bolts to the specified values (typically around 20-25 ft-lbs).

4. Clear Codes and Test

• Sub-step 1: Reconnect the battery.
• Sub-step 2: Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Sub-step 3: Start the engine and conduct a test drive to ensure the issue is resolved.