how to fix P0420 on Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety.
• Allow the exhaust system to cool down before beginning work.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Use a socket wrench to remove the oxygen sensors.
  3. Inspect the sensors for signs of carbon buildup or damage.
  4. If either sensor is faulty, replace it with an OEM equivalent sensor.

Tools Required:

• O2 sensor socket
• Socket wrench
• Torque wrench

3. Check and Repair Exhaust System

• Sub-steps:
  1. Visually inspect the exhaust pipe and catalytic converter for cracks or holes.
  2. If leaks are found, repair or replace the affected sections of the exhaust system.
  3. Ensure all connections are tight and sealed properly.

Tools Required:

• Wrenches
• Exhaust sealant (if applicable)
• Replacement exhaust parts (if required)

4. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields covering the catalytic converter by unbolting them.
  2. Unbolt the catalytic converter from the exhaust manifold and exhaust pipe.
  3. Install the new catalytic converter in reverse order, ensuring all bolts are torqued to manufacturer specifications (usually around 40-60 ft-lbs).

Tools Required:

• Socket set
• Torque wrench