how to fix P0420 code on Toyota Camry XV50 (2012-2017)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:
   • Use an oxygen sensor socket to unscrew the sensor from the exhaust manifold.
   • Disconnect the sensor wiring harness.
2. Install the new upstream oxygen sensor:
   • Apply anti-seize compound to the threads of the new sensor.
   • Screw it into the manifold and tighten to manufacturer's specifications (typically 30-40 ft-lbs).
   • Reconnect the wiring harness.
3. Repeat for the downstream oxygen sensor if it is suspected to be faulty.

3. Inspect or Replace Catalytic Converter

1. Check for physical damage:
   • Visually inspect the catalytic converter for dents, cracks, or rust.
2. Replace the catalytic converter if damaged:
   • Remove the exhaust manifold bolts and/or clamps holding the catalytic converter.
   • Detach the old catalytic converter.
   • Install the new catalytic converter using new gaskets and tighten to manufacturer's specifications (usually 25-35 ft-lbs).
3. Reconnect any exhaust hangers and ensure all connections are secure.

4. Reconnect Battery and Clear Codes

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code and any related codes.