Honda Accord 9th Generation (2013-2017) P0420 code what does it mean

Solution

1. Preparation

• Gather all necessary tools and parts, ensuring the vehicle is parked on a flat surface.
• Disconnect the battery to prevent any electrical shorts.
• Allow the engine to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream O2 sensor:
  1. Locate the upstream oxygen sensor on the exhaust manifold.
  2. Use the O2 sensor socket to unscrew it from the exhaust.
  3. Install the new O2 sensor, ensuring it is tightened to manufacturer specifications (typically 30 ft-lbs).
• Repeat the process for the downstream O2 sensor if necessary.

3. Examine and Replace the Catalytic Converter

• Tools Required: Socket set, cutting tool (if necessary), gaskets, exhaust sealant.
• Remove the catalytic converter:
  1. Locate the catalytic converter in the exhaust system.
  2. Unbolt any mounting brackets and exhaust flanges connecting the converter to the exhaust.
  3. If the converter is welded, use a cutting tool to remove it carefully.
• Install the new catalytic converter:
  1. Position the new converter in place and secure it with the previously removed bolts.
  2. Use new gaskets and apply exhaust sealant if needed for a proper seal.
  3. Torque the bolts to the manufacturer's specifications.

4. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operational temperature.