how to fix P0420 code on my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Screwdriver set
• Safety goggles and gloves

2. Inspect and Replace Oxygen Sensors

1. Remove the Upstream Oxygen Sensor:

   • Locate the upstream oxygen sensor (usually near the exhaust manifold).
   • Use a socket wrench to unscrew and remove the sensor.
   • Inspect the sensor for damage.

2. Install New Upstream Oxygen Sensor:

   • Apply anti-seize compound on the threads of the new sensor.
   • Screw in the new sensor by hand, then tighten it to the manufacturer’s specifications (typically around 30-40 ft-lbs).

3. Repeat for Downstream Oxygen Sensor:

   • Locate and remove the downstream oxygen sensor similarly.
   • Install the new sensor using the same method as above.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the Catalytic Converter:

   • Locate the catalytic converter.
   • Remove any mounting bolts or clamps securing it to the exhaust system using a socket set.
   • Carefully detach the converter from its position.

2. Install New Catalytic Converter:

   • Position the new catalytic converter in place.
   • Secure it with the mounting bolts or clamps, tightening to the manufacturer's specifications.

4. Final Checks

• Reconnect the negative battery terminal.
• Clear the P0420 code using the OBD-II scanner.
• Start the engine and allow it to reach operating temperature.